The head of the International Atomic Energy Agency says Iran is insisting that some of its uranium enrichment centrifuges be exempt from a freeze of its nuclear program.

Mohamed ElBaradei told reporters in Vienna Thursday, that he would report to the IAEA board that Iran has frozen most of its uranium enrichment activity, except for 20 centrifuges.

Iran's new request is partial reversal of a recent agreement with the European Union to suspend all enrichment activity.

The IAEA chief says said he hopes the dispute will soon be resolved.

The IAEA board is meeting to decide whether to refer Iran to the U.N. Security Council for possible sanctions over its nuclear program.

The United States says Iran is secretly developing nuclear weapons - a charge Iran denies.