ISFAHAN (Reuters) -- Iran said it would review an offer of talks on its nuclear program with the United States and five other world powers, even as it prepared to declare new progress in its disputed atomic activities.
The United States, Russia, China, France, Germany, and Britain said on April 8 that they would ask European Union foreign policy chief Javier Solana to invite Tehran to a meeting to find "a diplomatic solution to this critical issue."
"We will review it and then decide about it," Ali Akbar Javanfekr, a senior adviser to Iranian President Mahmud Ahmadinejad, told Reuters.
Underlining Tehran's determination to press ahead with its nuclear program, Ahmadinejad was expected to announce later on April 9 in the central city of Isfahan that Iran has mastered the final stage of atom fuel production.
The West suspects Iran is seeking to develop nuclear bombs. The Islamic Republic, which marks its National Nuclear Day, says it only aims to produce electricity.
The new U.S. administration of President Barack Obama is trying to reach out to Iran, offering a "new beginning" of diplomatic engagement after three decades of mutual mistrust.
The invitation to direct talks marked a major policy change in Washington, which under former President George W. Bush spearheaded a drive to isolate Iran over its nuclear work.
"We strongly urge Iran to take advantage of this opportunity to engage seriously with all of us in a spirit of mutual respect," the six powers said in a statement after a meeting of senior diplomats in London on April 8.
Iran has so far reacted cautiously to U.S. overtures since Obama took office in January, saying it wants to see a real shift in Washington's policies rather than a change in words.
Ahmadinejad said on April 8 that Iran sought "interaction and negotiation based on honor, justice, and respect."
Professor Mohammad Marandi at Tehran University said Iran probably would accept the invitation for talks "if there are no particular strings attached," but that Washington must recognize that Iran sees its nuclear program as peaceful and legitimate.
"I think the mere inclusion of American diplomats on the negotiating table is not enough," Marandi, who heads North American studies at the university, told Reuters.
While reaching out to Iran, the Obama administration has also warned of tougher sanctions if it continues to defy UN demands to halt sensitive nuclear work.
Iran, the world's fourth-largest oil producer, has repeatedly rejected Western demands to stop uranium enrichment, which can have both military and civilian purposes.
Analysts say Iran may be setting tough conditions for dialogue in a bid to buy time. Adding to uncertainty, it holds a presidential vote in June in which Ahmadinejad faces a challenge from a moderate politician seeking detente with the West.
One Iranian analyst said he expected Ahmadinejad to say in Isfahan, where Iran has a uranium-conversion facility, that it has perfected the last of several phases of fuel output, with the production of uranium pellets and fuel rods for reactors.
Iran has long been working on its uranium-enrichment capability to fuel its developing nuclear power program, which it says it needs so that it can export more gas and oil.
Foreign nuclear analysts believe Tehran has yet to prove it has mastered industrial-scale enrichment of uranium, the key to making fuel in large, usable quantities and the most technically difficult aspect of producing nuclear power.
The nuclear fuel cycle includes mining and milling of uranium ore, uranium enrichment, fabrication and use of nuclear fuel, reprocessing of used fuel, and disposal or management of radioactive waste or unreprocessed spent fuel.