Diplomats say international inspectors have found new traces of highly enriched uranium in Iran that could indicate Tehran is secretly seeking material for nuclear weapons.
News agencies quote the diplomats, speaking anonymously, as saying the United Nations atomic energy agency found the traces on samples from equipment used at a former research center (Lavizan) in Iran.
Highly enriched uranium is required for nuclear weapons. The sources said there could be other explanations for the traces, including contamination of equipment bought from abroad, but Iranian officials had not reported nuclear enrichment at the site.
An Iranian Foreign Ministry spokesman Hamid Reza Asefi dismissed the news reports today (Friday) as unimportant.
A U.S. State Department spokesman Sean McCormack says the reports, at a minimum, show that Iran has not been "straight" (truthful) with the International Atomic Energy Agency.
The U.S. has refused to take part in direct talks, but has given its European allies time to persuade Iran to halt all uranium enrichment activity or face possible U.N. sanctions.
Three EU countries -- Britain, France and Germany -- are preparing a package of incentives to persuade Iran to give up its nuclear ambitions. The package is expected to be presented to Tehran within weeks.
Iranian President Mahmoud Ahmadinejad said today the nuclear standoff is "just psychological propaganda" aimed at threatening his country.