TEHRAN/VIENNA, Nov 16: Iran pledged on Sunday to suspend its uranium enrichment programme to ease concerns that its nuclear programme is aimed at developing weapons, but warned that the freeze was only temporary.

The freeze will take effect on Nov 22.

And in Vienna, the UN nuclear watchdog partly cleared Iran on Monday of charges it tried to make a nuclear bomb.

Diplomats said this was a clear victory for Iran and would make it tough for Washington to force the United Nations' agency to refer Tehran's case to the UN Security Council at a meeting on Nov 25.

But the International Atomic Energy Agency (IAEA) did not dismiss the U.S. view that Tehran is secretly developing nuclear weapons, saying it could not rule out covert activities in Iran.

Hassan Rohani, Iran's chief nuclear negotiator, said the suspension would remain in place as long as talks with the European Union continued on a final resolution of the issue.

"One hour ago we submitted a letter to the IAEA," Mr Rohani told reporters after a meeting in Tehran with the ambassadors of Britain, Germany and France, which have been negotiating with Iran for several weeks on behalf of the European Union.

Receipt of the letter by the International Atomic Energy Agency, the United Nations nuclear watchdog, makes the scope and starting date of the suspension legally binding.

A senior EU diplomat close to the talks said Iran had agreed to all points covered in a preliminary agreement hammered out in Paris a week ago. "We have reached a full agreement regarding all the issues mentioned in the package," he said.

Iran, which denies U.S. accusations that it is secretly developing atomic weapons, had held up a final deal by demanding that it be permitted to continue the early stages of uranium conversion. The EU rejected this idea.

"The suspension is what the Europeans wanted, a full one," a diplomat close to the IAEA said.

The "EU Three" have said that, once the suspension begins, they will discuss a package of incentives with Iran - ranging from cooperation on peaceful nuclear technology to a possible trade deal - in return for Iran permanently giving up any activities that could be used to make bomb-grade material.

Mr Rohani's deputy Hossein Mousavian told reporters those talks would start on Dec 15.

However, questions remain, as Iran has continued to insist that it will never give up its "sovereign right" to enrich uranium, even while negotiating with the EU.

"We have accepted the suspension as a voluntary step and it does not create any obligations for us," Hossein Mousavian told Iranian state television.

Washington, which accuses Tehran of using its nuclear power programme as a front to develop nuclear weapons, wants the IAEA to refer the case upwards because Tehran concealed a uranium enrichment programme for 18 years.

Diplomats in Vienna said that, with a suspension in place, the United States would have only a handful of supporters on the IAEA's 35-member board for such a move.

IAEA REPORT: The IAEA report said: "All the declared nuclear material in Iran has been accounted for, and therefore such material is not diverted to prohibited activities," language which diplomats said clearly referred to possible work on weapons.