Iran, facing sanctions that could cripple its oil exports, has told world powers it wants to resume long-stalled talks with new initiatives, and France said it might be open to addressing suspicions about its nuclear program.
Tehran made the offer in a letter to the EU's foreign policy chief obtained by Reuters Thursday, a day after it trumpeted several advances in nuclear know-how and sent oil prices upward.
Iran's president vowed no retreat from its nuclear program Wednesday but state television announced the proposal to re-launch talks after a year's hiatus.
Iranian chief negotiator Saeed Jalili's letter said he would have new initiatives but did not spell them out. He made one reference to Iran's nuclear issue, without spelling out whether Tehran was prepared to negotiate on it.
French Foreign Minister Alain Juppe said that while the letter was ambiguous it seemed to signal the start of opening up from Iran with respect to discussing its nuclear activity.
A February 20-21 visit to Iran by top U.N. nuclear watchdog officials would help determine whether Tehran was serious about tackling international concerns, Juppe told reporters.
The U.N. team, led by the International Atomic Energy Agency's chief inspector, will again try to extract Iranian explanations, after three years of stonewalling, for an IAEA investigation driven by intelligence reports that suggest Tehran has researched sophisticated ways to build atomic bombs.
Jalili's letter was a reply to one from Ashton in October in which she said the big powers could meet with Iran within weeks if it was ready to engage seriously in meaningful discussions.
Jalili said he welcomed an earlier statement by Ashton on respecting Iran's right to the peaceful use of nuclear energy.
(A) constructive and positive attitude toward the Islamic Republic of Iran's new initiatives in this round of talks could open positive perspective for our negotiation, Jalili said in the brief English-language letter.
Therefore...I propose to resume our talks in order to take fundamental steps for sustainable cooperation in the earliest possibility in a mutually agreed venue and time.
Jalili urged a focus on a spectrum of various issues to lay groundwork for constructive, forward-looking cooperation.
Western officials said the powers were consulting on a response to Jalili's letter.
A British government source struck a cautiously positive note: The key issue last time was (Iranian) pre-conditions, and pre-conditions are not mentioned in (this) letter.
The White House said it was reviewing the letter and repeated there was time and space for diplomacy to resolve tensions between Tehran and the West.
The United States and its allies suspect Iran is seeking to develop nuclear weapons capability under cover of a declared civilian nuclear energy program, and believe Tehran has used talks only as a time-buying tool, not a pathway to agreement.
Iran says it is enriching uranium only for civilian purposes. But after the IAEA report in November, the United States and EU adopted sanctions meant to shut down Iran's oil export industry, the world's fifth largest.
The clampdown on Iranian oil would take full effect in July.
Ashton handles the Iran file on behalf of six world powers - the United States, Russia, China, Germany, France and Britain.
Negotiations have been frozen since a fruitless meeting in Istanbul in January 2011.
Iran's ambassador to Moscow, Seyed Mahmoud Reza Sajjadi, told a news conference that Tehran would accept no preliminary conditions for progress in any further talks.
He was responding to a question about a Russian suggestion that, as a first step toward a resolution of the standoff, Iran could take measures including freezing the number of its centrifuges for uranium enrichment at current levels in return for assurances it would face no additional sanctions.
Sajjadi also shrugged off Iran's shrinking oil trade, saying Iran would benefit from any ban on its crude exports by boosting domestic production of refined fuels.
Iranians will show the whole world how they can use an embargo as an opportunity, he said.
Iran proclaimed three nuclear achievements Wednesday - a new generation of centrifuge able to refine uranium three times faster than at present, a major increase in the number of centrifuges, and loading a research reactor with Iran's first batch of domestically produced fuel.
If Iran succeeded in introducing modern centrifuges for production, it could significantly shorten the time needed to stockpile enriched uranium, which can generate electricity or, if refined much more, produce nuclear explosions.
Western diplomats and analysts said the Iranian announcements were largely hype and bluff, noting that Iran had been trying to develop several newer versions of centrifuges for years without introducing them into production.
Israel accused Iran of being behind attacks on Israeli targets in India, Thailand and Georgia this week. Security experts said they appeared to be retaliation for a campaign of sabotage waged against Iran's nuclear program.
At least four Iranian nuclear scientists have been killed in recent years in attacks believed carried out by or for Israel's intelligence services. Some analysts also suspect it has been involved in explosions at military and nuclear facilities.
Lieutenant General Ronald Burgess, director of the U.S. Defense Intelligence Agency, said Thursday U.S. agencies believed Israel had not yet taken a decision to launch a full-scale military strike on Iranian nuclear sites.
Iran was expected to respond if attacked but was thought unlikely to start any military conflict, he said.
Iran's Oil Ministry denied a state media report that it had cut off oil exports to six EU states, while leaving open the option as a pre-emptive strike against an EU plan to launch an embargo on Iranian oil on July 1.
Whether erroneous or just premature, the report caused a spike in oil prices to their highest level since August.
Iran is the world's No. 5 oil exporter, with 2.6 million barrels going abroad daily, about a fifth of it to EU countries.
Western sanctions are spreading to block Iran's oil exports and central bank financing of trade, and Tehran has resorted to barter and other unorthodox ways to import staples like rice, cooking oil and tea, commodities traders say.
Iran bought almost half a million tonnes of wheat this week, they said Thursday, with private buyers in talks to import from Russia using roubles as payment.
The Obama administration is also pressing the European Union and SWIFT, the global organization that facilitates most of the world's cross-border payments, to expel Iranian banks from its network, a new step in the push to deprive Iran of funds, a U.S. official said Wednesday.
(Additional reporting by Steve Gutterman in Moscow, Dmitry Zhdannikov and Adrian Croft in London and Rachelle Younglai and Roberta Rampton in Washington; Writing by Mark Heinrich; Editing by Andrew Roche)