A newly disclosed letter from an official at the UN's nuclear watchdog says Iran has assembled some 1,300 centrifuges -- the machines that spin uranium gas into enriched material -- and eight cascades of the centrifuges are now operating at the facility at Natanz.
The letter was written to Iran by the IAEA's deputy director-general and head of the Department of Safeguards, Olli Heinonen.
The Iranian ambassador to the IAEA in Vienna, Ali Ashgar Soltanieh, told Reuters news agency that Iran was carrying out enrichment under safeguards implemented in Iran by the IAEA. He said Iran was awaiting the next official report on its activities from IAEA Director-General Muhammad el-Baradei.
"Our enrichment is continuing under the safeguards of the IAEA, the inspectors and cameras are controlling all activities, and the report of how many centrifuge machines and the latest status of the activities in Natanz will be reported by the director-general," Soltanieh said.
Iran's action to produce nuclear fuel is taking place despite UN Security Council sanctions imposed on Iran over its refusal to halt enrichment work.
Responding to the new disclosure, U.S. White House National Security Council spokesman Gordon Johndroe said Iranian leaders are continuing to defy the international community and are continuing to lead the Iranian people down a path of isolation.
THE COMPLETE PICTURE: RFE/RL's complete coverage of controversy surrounding Iran's nuclear program.
An annotated timeline
of Iran's nuclear program.