The United States imposed sanctions on Iran following the Islamic revolution of 1979, while more recent rounds of sanctions by the US and other entities were motivated by Iran’s alleged nuclear weapons program.

On Tuesday, Brent North Sea crude for November delivery was up six cents to USD 115.86, while New Yorks main contract, light sweet crude for November, gained 11 cents to hit USD 91.96 a barrel.

"We have concerns about the economy, in particular Europe exerting downward pressure, but supporting oil are the tighter sanctions on Iran from the EU," said Victor Shum, senior principal of Purvin and Gertz energy consultants in Singapore on Tuesday.

On Monday, EU foreign ministers agreed on a new round of sanctions against Iran over its nuclear energy program in spite of a UN warning against the humanitarian ramifications of the previous bans.

Currently the sanctions include an embargo on dealings with Iran by the United States, and a ban on selling aircraft and repair parts to Iranian aviation companies.

Despite illegal sanctions on Iran, the country has managed to easily find new substitutes for EU customers of Iranian oil and gas.

On 23 January 2012, the EU agreed to an oil embargo on Iran, effective from July, and to freeze the assets of Iran’s central bank.

The bloc’s new move comes in defiance of the UN chief’s recent remarks about the humanitarian ramifications of the previously imposed embargoes.

Ban Ki moon warned on October 5 that the West’s sanctions have mainly targeted the livelihood of the ordinary Iranian population.

The illegal US engineered sanctions have been imposed based on the unfounded accusation that Iran is pursuing non civilian objectives in its nuclear energy program.

Iran rejects the allegations, arguing that as a committed signatory to the nuclear Non Proliferation Treaty (NPT) and a member of the International Atomic Energy Agency (IAEA), it has the right to use nuclear technology for peaceful purposes.

NEW YORK (Reuters) – President Barack Obama will warn Iran on Tuesday that the United States will “do what we must” to prevent it acquiring a nuclear weapon, and appeal to world leaders for a united front against further attacks on US diplomatic missions in Muslim countries.

Amid accusations from Republicans, including Mitt Romney, that Obama’s policies have not slowed Iran’s nuclear march, the president used the U.

“It would threaten the elimination of Israel, the security of Gulf nations, and the stability of the global economy. It risks triggering a nuclear arms race in the region, and the unraveling of the non proliferation treaty. That’s why a coalition of countries is holding the Iranian government accountable. And that’s why the United States will do what we must to prevent Iran from obtaining a nuclear weapon.”.

Obama has been under fire for, so far, opting not to meet in New York with visiting Israeli Prime Minister Benjamin Netanyahu, whose prime area of international concern is Iran’s nuclear program.

He reference to Iran came toward the end of a speech otherwise devoted to addressing the recent tumult in the Middle East and North Africa, including the murder of the US ambassador to Libya and three other Americans in Benghazi.

The number of bilateral meetings President Obama is scheduled to attend during the United Nations General Assembly in New York.

Recalling Stevens’ time serving in the Peace Corps as an English instructor in Morocco, he said Stevens “came to love and respect” the people of the region and carried that commitment throughout his life.

The president went on to restate his administration’s support for the Arab Spring, calling it a “season of progress.

“But he said the recent violence and unrest is indicative of the difficulties along the way. “True democracy — real freedom — is hard work,” he said.Obama said leaders in the region are at a critical juncture, and urged them to choose the forces of hope over the forces of intolerance.”.

It is time to leave the call of violence and the politics of division behind,” Obama said. “On so many issues, we face a choice between the promise of the future, or the prisons of the past.

And America stands ready to work with all who are willing to embrace a better future.

“The president called on world leaders to “marginalize” those that stoke hatred of the West in order to further their own politics.And he continued to address the anti Islam film that is blamed for many of the recent demonstrations against US diplomatic posts — though that film may not have played much of a role in the attack on the US Consulate in Libya.While the president did not describe that attack as terrorism Tuesday, Romney did in a separate speech to the Clinton Global Initiative conference.Obama stressed that while he condemns the “crude and disgusting” video, America maintains the right to free speech.”.

There is no video that justifies an attack on an embassy,” the president said.Obama said the world now faces a choice “between the forces that would drive us apart, and the hopes that we hold in common.

NEW YORK—The attack on the US consulate in Benghazi, Libya, that killed the American ambassador to the country earlier this month "wasnt just a mob action," President Barack Obama said Monday.

“The last time Obama addressed the assembly, there was an air of hope surrounding the Arab Spring. US officials remain optimistic, but some also worry that the latest unrest is perhaps the dark side of the revolution. Obama used his U.N. address to urge leaders in the region not to let their hard fought gains be undermined by those peddling the politics of hate and division.The relationship between the Libya attack and the protests against an anti Islam film elsewhere in the region remains unclear. Obama, in an interview on Monday, said the Libya attack was not just a “mob action.

REUTERS – Iranian hackers have repeatedly attacked Bank of America Corp (BA.

President Carter called the hostages “victims of terrorism and anarchy”, adding that the “United States will not yield to blackmail”.

The attacks, which began in late 2011 and escalated this year, have primarily been “denial of service” campaigns that disrupted the banks’ websites and corporate networks by overwhelming them with incoming web traffic, said the sources.

Whether the hackers have been able to inflict more serious damage on computer networks or steal critical data is not yet known.

The sources said there was evidence suggesting the hackers targeted the banks in retaliation for their enforcement of Western economic sanctions against Iran.

Dagan said other measures conducted by Israel and the United States, which he did not elaborate on, had done enough to delay Iran’s quest for a nuclear weapon.

Tehran has publicly advertised its intentions to build a cyber army and encouraged private citizens to hack against Western countries.

The attacks on the three largest US banks originated in Iran, but it is not clear if they were launched by the state, groups working on behalf of the government, or “patriotic” citizens, according to the sources, who requested anonymity as they were not authorized to discuss the matter.

They said the attacks shed new light on the potential for Iran to lash out at Western nations’ information networks.

Bank of America, JPMorgan and Citigroup declined to comment, as did officials with the Pentagon, US Department of Homeland Security, Federal Bureau of Investigation, National Security Agency and Secret Service.

It also quoted national security officials saying the government of Iran was behind the slowdowns on the bank websites.

A US financial services industry group this week warned banks, brokerages and insurers to be on heightened alert for cyber attacks after the websites of Bank of America and JPMorgan Chase’s experienced unexplained service disruptions.

NBC News Thursday reported that last Friday, the Pentagon issued a highly classified intelligence document on Iranian cyber attacks against US financial institutions.

The Iran hostage crisis was a diplomatic crisis between Iran and the United States where 52 Americans were held hostage for 444 days from November 4, 1979, to January 20, 1981, after a group of Islamist students and militants took over the American Embassy in Tehran in support of the Iranian Revolution.

DISRUPTIVE CAMPAIGNDenial of service campaigns are among the oldest types of cyber attacks and do not require highly skilled computer programmers or advanced expertise, compared with sophisticated and destructive weapons like Stuxnet.

But denial of service attacks can still be very disruptive: If a bank’s website is repeatedly shut down, the attacks can hurt its reputation, affect customer retention and cause revenue losses as customers cannot open accounts or conduct other business.

Bank of America, Citigroup and JPMorgan Chase have consulted the FBI, Department of Homeland Security and National Security Agency on how to strengthen their networks in the face of the Iranian attacks, the sources said.

He was a senior editor and correspondent for United Press International for nearly a decade, and has covered the Department of Homeland Security since 2003.

When complaints are made by RTI activists, law enforcement personnel do not take appropriate action.

The Iranian attackers may have used denial of service to distract the victims from other, more destructive assaults that have yet to be uncovered, the sources said.

He’s currently an associate Vice President at George Washington University and heads the Homeland Security Policy Institute.

Bush, told Reuters that he knows of “cyber reconnaissance” missions that have come from Iran but declined to give specifics.

“It is yet to be seen whether they have the wherewithal to cause significant damage,” said Cilluffo, who is now director of the Homeland Security Policy Institute at George Washington University.

The hijackers also intentionally crashed American Airlines Flight 77 into the Pentagon in Arlington, Virginia, and intended to pilot the fourth hijacked jet, United Airlines Flight 93, into the United States Capitol Building in Washington, D.

Jim Lewis, a former US Foreign Service officer, said Iran has been testing its cyber technology against Israel and other Gulf states in recent years.

In recent years, the West’s stealth war on Iran’s nuclear program has been waged through sabotage, industrial explosions, cyberviruses, and targeted killings.

“It’s like the nuclear program: It isn’t particularly sophisticated but it makes progress every year,” said Lewis, who is a senior fellow at the Center for Strategic & International Studies.

(Additional reporting Mark Hosenball, Andrea Shalal Esa and Jim Wolf in Washington, Joseph Menn in San Francisco and David Henry in New York; Editing by Tiffany Wu and Steve Orlofsky).

While they do not represent a quantum leap in pressure, they address a potential weakness in the continuing effort: Iran’s increasingly adroit maneuvering to circumvent sanctions by selling its oil through foreign banks or for alternative means of payment, like gold.

The United States will now blacklist any financial institution that receives payments for Iranian oil, which will prevent Iran from using foreign banks or its national oil company, in lieu of the Central Bank of Iran, as an agent to process oil transactions.

The sanctions followed criticism from Republican presidential challenger Mitt Romney that the White House is failing to act strongly enough to stop Iran’s suspected pursuit of a nuclear weapons.

The United States remains committed to finding a diplomatic resolution to the standoff with Tehran, but is also determined to step up the pressure, Obama said in a statement accompanying his executive order authorizing the sanctions.

The Iran hostage crisis was a diplomatic crisis between Iran and the United States where 52 Americans were held hostage for 444 days from November 4, 1979, to January 20, 1981, after a group of Islamist students and militants took over the American Embassy in Tehran in support of the Iranian Revolution.

“If the Iranian government continues its defiance, there should be no doubt that the United States and our partners will continue to impose increasing consequences,” he said.

Obama’s new sanctions target foreign banks that handle transactions for Iranian oil or handle large transactions from the National Iranian Oil Company (NIOC) or Naftiran Intertrade Company (NICO), two key players in Iran’s oil trade.

That builds on oil trade sanctions signed into law in December that prompted buyers in Japan, South Korea and India to significantly cut purchases to avoid penalties.

China also cut purchases from Iran earlier this year due to a dispute over contract terms.

The new executive order has the same rules, providing “exceptions” to nations that have demonstrated significant cuts.

The Iranian banks, it said, are involved in terrorism and weapons proliferation.

“We expect that today’s action will have a significant chilling effect on the ability of Kunlun and Elaf to operate anywhere in the world,” David Cohen, the Treasury Department’s undersecretary for terrorism and financial intelligence told reporters.

CHINA WARNS OF CONSEQUENCES OVER SANCTIONSChina’s swift and angry reaction to the US sanctions highlighted its insistence that its extensive trade and energy deals with Iran should not be hurt by the nuclear stand off.

“The US has invoked domestic law to impose sanctions on a Chinese financial institution, and this is a serious violation of international rules that harms Chinese interests,” Chinese Foreign Ministry spokesman Qin Gang said in a statement.

The sanctions “will have a negative effect on bilateral Sino US cooperation” Qin said, without giving details.

Israeli Prime Minister Benjamin Netanyahu said this week that sanctions have not set back Iran’s nuclear program “one iota” and that “a strong military threat” was also needed.

Negotiations over Iran’s nuclear program are at a standstill after several months, leaving many lawmakers frustrated and administration officials conceding that the pressure campaign has not persuaded Iran’s leaders to change course.

But US officials argue that the sanctions are inflicting significant pain on Iran and further isolating the country.

Rhodes, a deputy national security adviser, who quoted Iran’s president, Mahmoud Ahmadinejad, as saying they were the toughest sanctions Iran had ever faced.

European and American sanctions have driven down its oil exports by 40 percent to 50 percent, depriving Iran of $9 billion in revenue every quarter, said Robert J.

Mark Dubowitz, the executive director of the Foundation for Defense of Democracies and a supporter of tougher sanctions, said the new measures were “a major upgrade of the sanctions regime.

But like other sanctions advocates, he said more steps are needed to blacklist Iran’s energy sector and require countries to further cut oil imports.

The US Congress has pushed for more oil linked sanctions, and on Tuesday negotiators agreed to a final package that will require the Obama administration to crack down on those who ship or insure Iranian oil cargoes, or who pay for oil using gold.

A Senate vote on the sanctions is expected to happen before Congress breaks at the end of the week for an extended recess.

(Additional reporting by Samson Reiny in Washington, and Chris Buckley and Sally Huang in Beijing.

Pious pronouncements from US officials of their desire for multilateral relations and negotiations could easily be undone by a crass corporate agenda.

While all this plays out, the crisis in the Persian Gulf, which most nations on it call the Arabian Gulf, remains at a low boil.

There was little coverage in the US media of last week’s terrible incident in which a US Navy security team aboard a non combatant refueling ship off Dubai, reportedly fearing an approaching fishing boat as a USS Cole style attack, fired on the craft with a .50 caliber machine gun, killing one Indian fisherman and wounding three others.

Which is odd, since Dubai police officials cast doubt on US claims around the incident.

The tension around Iran’s nuclear program continues, with the theocratic Iranian regime under increasing sanctions pressure and still not cooperating with the UN’s nuclear watchdog agency.

The right wing Israeli government bangs the anti Iran drum even louder following last week’s murder of Israeli tourists in Bulgaria, saying this is only the latest such attack in a global terrorist campaign.

While the Gulf crisis percolates with the defection of the centrist Kadima party from the short lived Israeli unity government and Israeli leaders saying last week’s murder of Israeli tourists in Bulgaria is just the latest example of global Iranian terrorism, events accelerated in the South China Sea crisis.

If so, it may be in retaliation for the assassinations of nuclear scientists and officials deeply involved in the disputed Iranian nuclear program, part of an apparent intelligence war underway between Israel and Iran.

And Vietnam and China have engaged in some fierce fighting in the South China Sea, with nearly a hundred Vietnamese killed.

The United States also voiced its concern over “unilateral moves” in the South China Sea where it says collective diplomacy is needed to resolve competing claims.

We very seriously doubt that the PRC can handle the US Navy in the South China Sea, in blocking mode or any other.

The official Xinhua News Agency reported earlier that Sansha’s jurisdiction covers just 13 square kilometers (5 square miles) of land, including other islands and atolls in the South China Sea around Yongxing, but 2 million square kilometers (770,000 square miles) of surrounding waters.

The Gulf still takes priority, because of Iran’s repeated threats to shut down the Strait of Hormuz, the world’s principal choke point for oil supply, if sanctions are not eased, and because Israel is in play and this is an American election year, with Mitt Romney and the warhawk right in the US and Israel constantly attacking Barack Obama as supposedly being weak on Israel.

A distracted America gives China a much freer hand as it seeks to establish dominance throughout the South China Sea.

The financial lifeline for Spain helped strengthen the euro to $1.2635 from $1.2507 late Friday in New York.

A stronger dollar makes commodities priced in dollars, such as crude, more expensive to investors with other currencies.

“Over the last three months we have seen a significant reemergence of the link between the euro and oil prices,” energy trader and consultant The Schork Group said in a report.

If slashed Iranian exports lead to a drastically reduced Saudi reserve, currently falling oil prices would succumb to a more bullish market this summer.

Oil prices dipped below $91 a barrel in European trading Wednesday after Iran agreed to allow inspectors to begin investigating its nuclear program.

2 nuclear negotiator, said Western powers must explain what concessions it will offer to Iran in return for a halt to upgrading enriched uranium to weapons grade, according to official IRNA news agency Sunday.

In exchange for discussing enrichment, Iran wants the West to ease sanctions which have made exporting its crude more difficult.

Iran is thesecond largest crude producer in the Organization of the Petroleum Exporting Countries, behind Saudi Arabia.

In other energy trading, heating oil was up 4.6 cents at $2.72 per gallon while gasoline futures rose 4.7 cents at $2.73 per gallon.

The financial lifeline for Spain helped strengthen the euro to $1.2635 from $1.2507 late Friday in New York.

A stronger dollar makes commodities priced in dollars, such as crude, more expensive to investors with other currencies.

“Over the last three months we have seen a significant reemergence of the link between the euro and oil prices,” energy trader and consultant The Schork Group said in a report.

In particular, an arcane insurance ban on tankers contained in European sanctions could force so much Iranian crude off the market that oil prices could spike.

Oil prices dipped below $91 a barrel in European trading Wednesday after Iran agreed to allow inspectors to begin investigating its nuclear program.

2 nuclear negotiator, said Western powers must explain what concessions it will offer to Iran in return for a halt to upgrading enriched uranium to weapons grade, according to official IRNA news agency Sunday.

In exchange for discussing enrichment, Iran wants the West to ease sanctions which have made exporting its crude more difficult.

Iran is thesecond largest crude producer in the Organization of the Petroleum Exporting Countries, behind Saudi Arabia.

In other energy trading, heating oil was up 4.6 cents at $2.72 per gallon while gasoline futures rose 4.7 cents at $2.73 per gallon.

The policy shift came just days before high level meetings between Secretary of State Hillary Clinton and Treasury Secretary Timothy Geithner and their Chinese counterparts in Beijing.

In her opening remarks to the two day US China Strategic and Economic Dialogue, Clinton pressed China on human rights but avoided mention of Chen Guangcheng, a blind rights activist who sought protection in the US embassy until he left under a deal to stay in China – a deal he later said he regretted.

The Iran hostage crisis was a diplomatic crisis between Iran and the United States where 66 Americans were held hostage for 444 days from November 4, 1979, to January 20, 1981, after a group of Islamist students and militants took over the American Embassy in Tehran in support of the Iranian Revolution.

Nor did Chinese officials make any such threats to us,” State Department spokeswoman Victoria Nuland told NBC News.  . “At every opportunity, he expressed his desire to stay in China, reunify with his family, continue his education and work for reform in his country.

“It is critical that we keep the pressure on Iran to meet its international obligations, negotiate seriously, and prove that its nuclear program is solely for peaceful purposes,” she said.

China, the biggest consumer of Iranian oil exports, also continues to exchange key technologies with Iran in violation of US sanctions.

China has also resisted calls from Washington and its Asian allies for stronger pressure on North Korea, its neighbor and long time ally that recently launched a rocket that the U.

But the “straw that broke the camel’s back” and prompted the White House’s policy shift on Taiwan might have been recent reports claiming Beijing supplied North Korea with critical weapons technology, said Patrick Cronin, an expert in Asian Pacific security issues at the Center for a New American Security.

Clinton said Washington and Beijing should “work together to make it clear to North Korea that strength and security will come from prioritizing the needs of its people – not further provocation.

Weighing fighter sales to Taiwan can “really can throw a wrench in the ability to move forward” on a number of pressing issues concerning North Korea, Syria and Iran.

“But the uproar over the dissident Chen hovered over the opening of the US China talks.Chen left the US embassy on Wednesday after Washington said it had won assurances from Beijing about his safety following his escape from 19 months of captivity in his home.But Chen later said he feared for his safety and wanted to leave for the United States.”.

Beijing’s relations with Tehran will almost assuredly grow stronger if the United States does end up supplying fighters to Taiwan.

President Carter called the hostages “victims of terrorism and anarchy”, adding that the “United States will not yield to blackmail”.

We believe all governments have to answer our citizens’ aspirations for dignity and the rule of law and that no nation can or should deny those rights.

Mark Fitzpatrick, a director of the International Institute for Strategic Studies think tank, said getting Iran to halt 20 percent enrichment would be an interim goal “to put a lid on the most troublesome” aspect of Iran’s nuclear programme.

Iran’s deputy negotiator Ali Baqeri held separate talks with senior Chinese and Russian officials in Istanbul, and the six powers met internally to coordinate tactics.

SUSTAINED PROCESSThe formal talks between Jalili and European Union foreign policy chief Catherine Ashton, the powers’ main representative, will get under way on Saturday, but Ashton and Iranian chief nuclear negotiator Saeed Jalili will meet over dinner on Friday.

The West accuses Iran of seeking to develop a nuclear weapons capability and Israel – believed to be the only Middle East state with an atomic arsenal – has hinted at pre emptive military strikes to prevent its foe from obtaining such arms.

They said that the benchmark for success would be whether there was enough common ground by Saturday night to justify a second round of talks within the next few weeks.

If Iran were to accept scaling back its uranium enrichment programme, it would probably expect to be rewarded with a relaxation of sanctions, for example the lifting of an EU oil embargo due to take effect in less than three months time.

Western diplomats have expressed cautious optimism that Iran, which has seen its economically vital oil exports squeezed by increasingly tough sanctions, may finally be ready to discuss curbs to its nuclear programme to relieve the pressure.

The meeting is widely seen as a chance for the countries involved – the United States, France, Russia, China, Britain and Germany – and Iran to halt a downward diplomatic spiral and to seek ways out of years of deadlock.

Despite the concerns about supplies from Iran — including an oil embargo by the US and the European Union — the International Energy Agency said that during the first three months of 2012 demand weakend while output from OPEC countries increased.

The punitive measures are not due to take effect for two months but they have already had a profound effect on the Iranian economy, triggering a run on the currency and forcing Iran to sell its oil at a steep discount to its remaining buyers in Asia.

In our opinion, and from our observations, the Iranian people want nuclear energy because they want Iran to sell its gas and oil abroad to generate income.

“The strength of the oil sanctions have taken them by surprise. They have really been hit by them,” a western diplomat said in Istanbul.

A long term deal will have to “provide confidence that Iran cannot quickly produce nuclear weapons,” he told Reuters, adding this would require both better monitoring of Iran’s nuclear work and limits on its uranium enrichment and stockpiles.

Iran has signalled some flexibility over halting its enrichment to a fissile purity of 20 percent – compared with the 5 percent level required for nuclear power plants – but also suggests it is not ready to do so yet.

(The percentages refer to the concentration of the most fissile uranium isotope, U 235).

Tehran said the purer fuel would be used in a research reactor in Tehran for the production of medical isotopes.

However, the move raised tensions dramatically as it brought Iran much closer to a capacity to make weapons grade uranium.

Iran also began making the higher enriched fuel in a deeply buried plant at the Fordow military site, near Qom, triggering Israeli threats of military action before the Iranian programme could enter what the Israeli defence minister, Ehud Barak, has called a “zone of immunity” from attacks from the air.

One ominous line in that New York Times piece was: “Mr Obama and his allies are gambling that crushing sanctions and the threat of Israeli military action will bolster the arguments of those Iranians who say a negotiated settlement is far preferable to isolation and more financial hardship.”.

Western diplomats at the Istanbul talks said the most likely Iranian offer would be to limit the production of 20% enriched uranium in return for sanctions relief.

But the head of the Atomic Energy Organization of Iran, Fereydoon Abbasi Davani, suggested Iran might be willing to cap its production of uranium enriched to 20% purity, near weapons grade, in exchange for economic assistance from the West.

Foreign ministers from the Group of Eight (G8) industrialized nations called on Iran Thursday to engage in “constructive and serious dialogue” and comply with its obligations to resolve the dispute over its nuclear programme, dpa reported.

It is believed to have enriched enough 20% uranium already to keep the Tehran research running for eight years.

Quoted by Iran’s official news agency IRNA, Russian Deputy Foreign Minister Sergei Ryabkov said there was still no concrete proof Iran’s nuclear work had a military dimension.

Iranian Foreign Minister Ali Akbar Salehi, in a rare opinion piece in a US newspaper, said his country hoped that all sides would commit to comprehensive dialogue and that negotiators make “genuine efforts to re establish confidence and trust”.

“To solve the nuclear issue, the scope of the upcoming talks … must be comprehensive. The concerns of all sides must be addressed.”.

If Iran does table a substantive offer, it could bring to the surface longstanding differences among the six nations.

At an initial meeting of the six delegations, the Russians recommended lifting some sanctions as a goodwill gesture.

But western participants said the international community could not give up its main bargaining chip for nothing in return.

European diplomats said that although the EU oil embargo does not take full effect until 1 July, the political decision had been taken and it would be almost impossible to stop.

Ashton’s office is uneasy about reports in the US that Washington and its allies would demand the cessation of production of 20% uranium, the export of Iran’s 20% stockpile, and the closure of Fordow as an opening position at the Istanbul talks.

The lede of the Times story is that the Obama administration and its European partners will open the talks by demanding the immediate closing and ultimate dismantling of Irans uranium enrichment facility at Fordo.

That is not the joint policy of the six nation group, which for now is simply to sound out the Iranians on their willingness to negotiate.

European diplomats say they have been assured by US colleagues that the US reports did not represent their position, and speculated that they reflected posturing for US domestic consumption in an election year.

The US secretary of state, Hillary Clinton, said Washington was “looking for concrete results” from Iran.

We want them to demonstrate clearly in the actions they propose that they have truly abandoned any nuclear weapons ambition.

France, which has consistently taken the hardest line of the six nation group, has expressed concern privately that a deal on 20% uranium could imply that the international community accepted Iran’s production of 3.5%-enriched uranium, in contravention of UN security council resolutions.

“We really do not have a common view of what’s the real offer to be made to Iran to bring it to serious negotiations,” the Russian deputy foreign minister, Sergey Ryabkov, said this week at a meeting in Washington, according to the Washington Post.

LONDON (Reuters) – Iran is concealing the destinations of its oil sales by disabling tracking systems aboard its tanker fleet, making it difficult to assess how much crude Tehran is exporting as it seeks to counter Western sanctions aimed at cutting its oil revenues.

He estimated concern that Iran’s crude exports will be cut by a military conflict or tighter sanctions has added about $15 to the price of oil.

Most of Iran’s 39 strong fleet of tankers is now “off radar” after Tehran ordered captains in the National Iranian Tanker Co (NITC) to switch off the black box transponders that are used in the shipping industry to monitor vessel movements, oil industry, trading and shipping sources said.

“Iran, helped by its customers, is trying to obfuscate as much as possible,” said a senior executive at a national oil company that has done business with Iran.

And Iran may have countered a reported reduction in its oil sales in March by offering big discounts in the form of free freight, finance and insurance and generous credit terms, the sources said.

Oil prices inched above $103 a barrel Thursday, tracking a rise in financial markets, while traders turned their attention to negotiations this weekend over Iran’s nuclear program.

But cheap, covert sales may have curbed or even reversed the reduction in shipments, the sources say.

Ship captains steering NITC supertankers have switched off recognition systems and customers are keeping business strictly under wraps.

“People are being very secretive right now. They are not talking about this on email, Yahoo or mobile,” said the head of a crude oil desk at a top oil trading houses.

A Reuters’ survey of the Iranian fleet via the ship tracking system AIS Live shows only seven of its 25 very large crude carriers are still operating their on board transponders, which allow computers to track vessels.

Only two of NITC’s nine smaller Suezmax size tankers now have their tracking systems in operation, shipping sources say.

“NITC oil tankers are going to operate in stealth mode,” said a shipping official, who declined to be identified.

Under normal circumstances, tankers would generally not turn off their tracking systems.

Some did so last year during the Libyan civil war in order to trade with the Gaddafi government.

As sanctions make it harder to pay for and ship oil from Iran, it is increasingly difficult to gauge how much is moving out of the country’s main terminal at Kharg Island.

Crude exports in thesecond biggest producer of the Organization of PetroleumExporting Countries averaged about 2.2 million barrels a day in2010, according to the US Department of Energy.

But that has been hard to square with tanker tracker data and market intelligence.

Expert opinion is that Iran’s visible crude oil sales fell to about 1.9 million bpd in March.

Despite the concerns about supplies from Iran — including an oil embargo by the US and the European Union — the International Energy Agency said that during the first three months of 2012 demand weakend while output from OPEC countries increased.

The trouble is there is no hard evidence that Iran’s oil production has actually fallen or that it is going into storage.

Millions of barrels of Iranian oil that were in storage in Iranian tankers a few weeks ago now seem to have disappeared, ship tracking data shows.

?”It’s the million dollar question – the billion dollar question even,” a senior executive in Asia at a large oil trading house said.

The hunt is getting more complicated as OPEC’s second biggest producer comes up with a range of tactics to avoid scrutiny.

“Some big Asian companies may be taking oil on Iranian ships provided they switch off the transponders,” said another European shipping industry source.

A trader in Singapore said Iran has managed to sell all the crude stored on half a dozen vessels floating off Singapore earlier in the year.

Given the lack of visibility of NITC’s fleet, it will become increasingly difficult to measure floating storage.

Industry sources say parts of the fleet were storing up to 12 million barrels of crude in March.

BIGGER FLEETTehran is about to have greater flexibility in disguising the locations for oil sales.

NITC will take delivery of the first of 12 new supertankers to be delivered from China in May.

Iran does not have the capacity by itself to ship all of its exports, either chartering more ships or leaving it to importers to hire their own vessels.

It has long been assumed Iran would sell most of the oil shunned by Europe to China, its long term strategic and commercial ally.

However, oil has slid from $110 last month amid optimism meetings between Iran and the US, France, Britain, Russia, China and Germany that begin Saturday in Turkey could ease tensions.

India, however, has been buying oil on Iranian ships on extended credit for several months, industry sources say.

TheUS is imposing sanction on Iran’s oil export,” Ye said. “Thisyear, we will continue to be cautious about Iranian crudeimports.

“China and India are our lifters of last resort,” said an Iranian oil official, who declined to be identified.

IRST is defined by the 52.5 degrees east meridian, the same meridian which defines the Iranian calendar and is the official meridian of Iran.

The senior oil trading executive agreed: “We think China is taking most of the Iranian overhang and is keeping very quiet.”.

China’s imports in April should climb back to contract volumes of around 560,000 bpd after a cut to half that in the first quarter when Chinese refiner Sinopec reduced purchases to negotiate better prices with the National Iranian Oil Company.

If Iran is using its own ships to deliver oil to customers, paying for the freight charges, that would be worth nearly $5 million per voyage.

Traders say Iran is sometimes also covering insurance, increasingly difficult to finance on international markets.

Buyers are also demanding, and often getting, much better credit terms from the National Iranian Oil Co (NIOC) than normal – as long as six months to pay for each cargo of 2 million barrels.

(Additional reporting by Jonathan Saul; Editing by Richard Mably and Giles Elgood)(This story corrects estimates for visible Iranian oil exports in paragraphs 16 and 18).