Iran said on Tuesday there was no going back on its decision to restart nuclear fuel work, a move a French minister said could spark a major international crisis.
Two years of hard bargaining between the European Union and Iran over its nuclear program looked close to breaking point with the EU coming round to the U.S. view that Tehran should be referred to the United Nations for possible sanctions.
"I think this Iranian affair is very serious and that it could be the start of a major crisis," French Foreign Minister Philippe Douste-Blazy told reporters in Paris.
The United States says Iran is trying to build a nuclear arsenal under the veil of a civilian atomic fuel program. Iran says it only wants to build nuclear power stations.
The so-called EU3 of Britain, France and Germany had been due to offer Iran nuclear, political and economic incentives to freeze its nuclear fuel activities indefinitely.
But Iran insists the EU recognize its right to enrich uranium, something the union has so far refused to do, reports Reuters.
France and Washington now appear to be in agreement on referring Iran to the UN Security Council.
On Monday White House spokesman Scott McClellan said: "If they're not going to abide by their agreement and obligations, then we would have to look to the Security Council," informs BBC.
According to Ali Aghamohammadi, the process will go on without delay. "The resumption is irreversible," he said.
"The political decision has been taken. We have handed over the letter to the IAEA (International Atomic Energy Agency)."
The head of the IAEA appealed to Iranian officials Monday not to resume uranium work and to give the European Union countries more time to negotiate an extension of the November agreement.
"I also call on Iran not to take any unilateral action that could undermine the agency inspection process at a time when the agency is making steady progress in resolving outstanding issues," said Mohamed ElBaradei, director-general of the Vienna-based nuclear watchdog.
But IAEA spokeswoman Melissa Fleming told CNN that the agency received a request from Iran on Monday to remove the agency's seals from its conversion equipment.
"We've answered that request by saying it would take us more than a week to put our surveillance equipment in place, asked them to refrain from removing any of the seals that would enable us to make sure the equipment hasn't been touched," Fleming said, reports CNN.