Iran has long insisted its program is peaceful, though it is the only non-nuclear-armed nation enriching uranium at that level. The U.S., the IAEA and others say Iran had a nuclear weapons program up until 2003.

Officials in Washington believe Tehran is deliberately running down the clock before the Europeans decide whether to reimpose 'snapback' sanctions under the terms of the 2015 nuclear deal

Iranian Foreign Minister Abbas Araqchi and his French, British and German counterparts agreed on Friday to resume talks next week on nuclear and sanctions issues, Iranian state media reported.