VIENNA -- Iran has met a key commitment under a preliminary nuclear deal setting up the current talks on a final agreement, leaving it with several tons less of material it could use to make weapons, according to a report issued Wednesday.
The confidential International Atomic Energy Agency report said more than 4 tons of the enriched uranium had been fed into a pipeline that ends with conversion of it into oxide, which is much less likely to be used to make nuclear arms.
The report indicated that only several hundred pounds of the oxide that is the end product had been made. But a U.S. official said the rest of the enriched uranium in the pipeline has been transformed into another form of the oxide that would be even more difficult to reconvert into enriched uranium, which can be turned into the fissile core of nuclear arms.
The official said technical problems by Iran had slowed the process, but the United States was satisfied that Iran had met its commitments to reduce the amount of enriched uranium it has stored. He demanded anonymity because he was not authorized to discuss the confidential review process.
Iran repeatedly has said its nuclear program is meant only to fuel reactors and for other nonmilitary purposes. But the country is seeking a deal with the U.S. and five other world powers that would put long-term caps on Iran's nuclear program in exchange for relief from economic sanctions.
Meeting conditions of the preliminary deal is an important benchmark. Violations by Iran would complicate the argument by President Barack Obama's administration that U.S. negotiators are holding the line on demands for a verifiable deal that extends the time Iran would need to make a weapon to at least a year.
The report did not say where the rest of the material was, but it appeared to confirm the U.S. official's description of the material being somewhere in the conversion line. That's because the figures provided by the International Atomic Energy Agency indicated it was not added to Iran's stockpile of low-enriched uranium.
Low-enriched uranium can be enriched further for weapons purposes. The interim accord capped Iran's low-enriched uranium stockpile at 7.6 tons. If it went over that limit, it would have to convert the remainder into oxide.
The atomic agency's report said the stockpile was just under that level as of Tuesday.
The report was circulated among the 35-nation agency's board and the United Nations Security Council, as the agency's chief left for Tehran to meet with Iranian President Hassan Rouhani and U.S. Secretary of State John Kerry in Vienna.
In his talks today in Tehran , atomic agency chief Yukiya Amano said he hopes to "accelerate the resolution of all outstanding issues related to Iran's nuclear program, including clarification of possible military dimensions," the Vienna-based agency said in a statement.
Iran's Mehr news agency said Amano will "receive Iran's alternative proposal" to the proposed questioning of its nuclear scientists, a step Supreme Leader Ayatollah Ali Khamenei has called a red line.
An International Atomic Energy Agency probe of allegations that Iran worked secretly on nuclear arms has been essentially stalemated for nearly a decade.
Kerry's meeting with Iranian Foreign Minister Mohammad Javad Zarif was the first since world powers agreed to extend the nuclear talks until Tuesday.
"We will continue, and we will make progress," Zarif said. "We have made progress, and we will make progress, and we will use every opportunity to make progress."
Kerry also spoke of progress despite "some very difficult issues."
The June 30 deadline originally had been envisioned as the culmination of nearly a decade of diplomacy aimed at assuring the world Iran cannot produce nuclear weapons, and providing the Iranian people a path out of their international isolation.
But officials said over the weekend that they were nowhere near a final accord.
In Washington, Obama said there would be no nuclear deal with Iran if inspections and verification requirements are inadequate.
Information for this article was contributed by Bradley Klapper of The Associated Press.
A Section on 07/02/2015