Iran is seeking exemptions from a deal to suspend sensitive nuclear activities that could be used to make weapons just three days after it came into force, the head of the UN atomic watchdog said today.
Tehran's request threatened to torpedo the hard-won agreement with the European Union and further antagonise Washington, just as the International Atomic Energy Agency (IAEA) began meeting to review Iran's atomic programme.
IAEA head Dr Mohamed ElBaradei said Iran had suspended activities related to enriching uranium, except for 20 centrifuge machines on which it wanted to conduct research without using nuclear material.
Centrifuges spin at supersonic speed to enrich, or purify, uranium for use in nuclear reactors. Uranium enriched to a very high degree can be used in a nuclear weapon.
Iran says it wants to use nuclear power solely for peaceful purposes, and denies US accusations that its civilian programme is a cover for building a bomb.
Anxious to avoid being referred to the UN Security Council for possible sanctions, Tehran said on Monday it had suspended the "whole enrichment process" in line with an agreement with Germany, France and Britain.
"I'm going to report that we have completed our work with regard to verification of the suspension with one exception, the request by Iran to exempt 20 centrifuges for (research and development) without using nuclear material," Dr ElBaradei said.
He hoped the dispute would "resolve itself" within 24 hours.
The IAEA has tried not get involved, saying the diagreement was between Iran and the EU. But diplomats on the IAEA's 35-member board said the dispute was serious.
"This is a big problem," said a Western diplomat close to the negotiations between the EU and Iran. "It has to do with the definition of a full suspension."
The diplomat said IAEA inspectors ran into difficulties in Iran on Wednesday when the Iranians refused to let them seal the centrifuges to prevent them being used.
IAEA spokesman Mr Mark Gwozdecky confirmed this, and said that the centrifuges were at the Natanz enrichment plant, a facility which Tehran had kept secret from the UN until a group of Iranian exiles revealed its existence in August 2002.
"Iran wants to keep using (the centrifuges) for research and development but this is impossible under the EU deal," said one diplomat.