The threat came just hours after world powers referred the crisis back to the Security Council for possible sanctions over a failure by Iran to respond to demands that it suspend work that could lead to the production of nuclear weapons.

"Up to now the Iranian people have acted within the framework of the NPT and the IAEA," the president said in reference to the nuclear Non-Proliferation Treaty and the UN's International Atomic Energy Agency.

"But if they reach the conclusion that Western countries do not have goodwill and sincerity... they (the Iranian people) will revise their policy," Ahmadinejad said in comments carried by Iranian state television's website.

Iran says it wants to enrich uranium only to make reactor fuel, and rejects accusations that it wants to acquire the capacity to make nuclear weapons.

But on Wednesday the five permanent members of the UN Security Council plus Germany decided they had lost patience with Tehran.

"The Iranians have given no indication at all that they are ready to engage seriously on the substance of our proposals," French Foreign Minister Philippe Douste-Blazy said in a statement agreed with his colleagues from the United States, Britain, Germany, Russia and China.

Iran had been offered trade, diplomatic and technology incentives as well as multilateral talks involving the US if it agreed to a suspension.

"We express profound disappointment over this situation," Douste-Blazy said. "We have no choice but to return to the United Nations Security Council."

The US ambassador to the UN, John Bolton, said he hoped the Security Council would be able to take action "early next week" on a draft resolution that would make a halt to Iranian uranium enrichment mandatory.

"China has agreed, Russia has agreed" on the steps to be taken, a senior US official also said, adding that specific sanctions had not yet been decided.

But Ahmadinejad told the world powers to "be patient and not disturb the current climate", arguing that Iran was still looking into the offer.

"We will try to conduct a positive examination (of the offer) and will give our reply at the end of Mordad," the Iranian month that ends on August 22, he was quoted as saying.

"We want to solve the problem calmly," he said, rejecting Western accusations that Iran's hardline leadership was merely trying to buy time and exploit international divisions.

But the president also repeated that "we will not renounce our absolute right to use peaceful nuclear technology" -- in yet another signal the Islamic republic was unwilling to freeze enrichment.

Iran resumed enrichment in January, and has already ignored a non-binding Security Council demand for the work to cease pending the result of a three-year-old and still inconclusive IAEA investigation.

Iranian leaders have already moved to limit IAEA inspections, and have in the past threatened to follow the path of North Korea by abandoning the NPT -- the cornerstone of the global effort to halt the spread of nuclear weapons.

"It has to be understood that any tough action will be to the detriment of all parties," Foreign Minister Manouchehr Mottaki told a joint news conference with his visiting South African counterpart Nkosazana Dlamini-Zuma.

"Iran wants to keep the calm, and we advise (the major powers) to stay calm and avoid taking any action that increases pessimism," he added.

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