VIENNA The United States said on Wednesday Iran was nearing the ability to make atom bombs by stockpiling enriched uranium and, with EU allies, prodded Tehran to engage in talks now on its nuclear ambitions.
Western powers spoke at a U.N. nuclear watchdog meeting as Iran's state television announced that it would hand over a long-delayed package of proposals for talks "very soon" amid Western talk of pursuing far harsher sanctions against Tehran.
"We have serious concerns that Iran is deliberately attempting, at a minimum, to preserve a nuclear weapons option," U.S. envoy Glyn Davies told the 35 nations on the International Atomic Energy Agency's Board of Governors.
"Iran is now either very near or in possession already of sufficient low-enriched uranium to produce one nuclear weapon if the decision were made to further enrich it to weapons-grade ... (This) moves Iran closer to a dangerous and destabilizing possible breakout capacity," Davies said.
U.S. national intelligence chief Dennis Blair estimated earlier this year that Iran probably would be unable technically to "weaponize" enrichment before 2013.
IAEA Director-General Mohamed ElBaradei has said Iran's threat has been exaggerated. But Davies' remark pointed to growing Western disquiet about Iran's nuclear advances, largely out of sight due to restrictions on U.N. inspections.
An August 28 IAEA report said Iran had somewhat improved transparency by approving tighter monitoring of its Natanz enrichment plant and allowing inspectors to revisit a reactor site of proliferation concern after a year-long ban on access.
Iran had also slightly reduced, as of mid-August, its number of centrifuge machines refining uranium, the report said, a move diplomats said pointed to repair and maintenance work.
RISK ASSESSMENT RISING
But the IAEA also said Iran had raised its total number of installed centrifuges by 1,000 to 8,300, expanding potential enrichment capacity, and was still blocking an IAEA inquiry into allegations it has tried to "weaponize" the enrichment process.
"The reduction in enriching centrifuges was just a snapshot, and probably means peanuts to the overall picture. The big powers base their risk assessment of Iran on the number of installed machines," a senior U.N. official told Reuters.
Iran has said its package for world powers addresses global "challenges" but also reaffirmed an unwillingness to negotiate on its campaign to enrich uranium, a process Western powers suspect Iran will eventually put to making atom bombs.
Iran says it seeks only electricity from enrichment.
Britain, France and Germany, among the six powers dealing with Iran, said its "persistent defiance and point-blank refusal" to halt enrichment and avoidance of talks demanded by U.N. Security Council resolutions, was unacceptable.
"We would review any proposal seriously in the spirit of mutual respect and welcome the Iranian government's constructive response to the P5+1's April 2009 invitation to meet face to face," said Davies, Washington's IAEA ambassador.
U.S. President Barack Obama has indicated Iran will face much harsher sanctions, targeting its vital oil sector, if it does not accept negotiations by the end of September.
(Editing by Ralph Boulton)