The US and Britain said Wednesday that Western countries will likely seek Iran's referral to the UN Security Council after it restarted nuclear activity.
Iran's president said his country would not be bullied and would push ahead with the program.
British Prime Minister Tony Blair said he could not rule out the possibility that Iran will face economic sanctions.
International impatience with Iran was growing after it broke UN seals at a uranium enrichment plant Tuesday and said it was resuming nuclear research after a two-year freeze. Enriched uranium can be used as a fuel for both nuclear energy and nuclear weapons.
"I think the first thing to do is to secure agreement for a reference to the Security Council, if that is indeed what the allies jointly decide, as I think seems likely," Blair told the House of Commons in London, adding that he was in close contact with Washington on the issue.
"We obviously don't rule out any measures at all," Blair said when asked about possible sanctions. "It's important Iran recognizes how seriously the international community treats it."
State Department spokesman Sean McCormack said "it is more likely than ever" that the UN nuclear watchdog, the International Atomic Energy Agency, will refer Iran to the Security Council. The council could then impose sanctions.
White House spokesman Scott McClellan said Tuesday if Iran continued on its present course, "there is no other choice but to refer the matter to the Security Council."
McCormack said Secretary of State Condoleezza Rice had discussed the situation by telephone with IAEA chief Mohamed ElBaradei and British Foreign Secretary Jack Straw.
Russia, a longtime ally of Iran, expressed anger as well. Foreign Minister Sergey Lavrov talked with Rice, and both sides shared "a deep disappointment" over Iran's move, the Russian Foreign Ministry said.
But Iranian President Mahmoud Ahmadinejad shrugged off the international outcry.
"Unfortunately, a group of bullies allows itself to deprive nations of their legal and natural rights," Ahmadinejad told a crowd during a visit to the port city of Bandar Abbas. His speech was broadcast live on state-run television. "The Iranian nation is not frightened by the powers and their noise."
Former President Hashemi Rafsanjani took a sharper tone, denouncing the West's "colonial policy."
"If they cause any disturbance, they will ultimately regret it," the cleric warned in a speech for the Islamic holiday of Eid al-Adha aired on state TV.
"Even if (the Westerners) destroy our scientists, their successors would continue the job," he said. "It would not be easy for them to solve the (nuclear) case by imposing sanctions or anything like that."
Rafsanjani, who was Iran's president in the 1990s, lost to Ahmadinejad in a runoff election in June. The policy of pursuing the nuclear program has become a point of national pride for many Iranians, a rare issue that crosses the reformist-conservative divide.
Rafsanjani now serves as head of the Expediency Council, a powerful body that mediates between the elected parliament and Iran's unelected Islamic clerical leadership, which holds ultimate say in the country.
Iran insists its research is for peaceful energy production only. But the United States suspects Tehran has ambitions to produce nuclear weapons.
"I tell those superpowers that, with strength and prudence, Iran will pave the way to achieving peaceful nuclear energy," Ahmadinejad said. "In the near future, (nuclear) energy will be completely carried out by the Iranian nation."
The president accused the West of seeking to prevent Iran's technological development and control the country by forcing it to buy nuclear fuel abroad.
"They falsely say that they oppose nuclear weapons. They want to have nuclear monopoly to sell it drop by drop at an expensive price and use it as an instrument for domination over nations," he said.
Blair said Iran's decision to restart its nuclear program, coupled with Ahmadinejad's recent inflammatory comments about Israel, "cause real and serious alarm right across the world." Ahmadinejad recently called for Israel to be "wiped off the map" and said the Holocaust was a "myth."
German Deputy Foreign Minister Gernot Erler cautioned against referring the dispute to the Security Council, saying it could further destabilize the Middle East.
Foreign ministers from Britain, France and Germany, who have spent two years trying to persuade Iran to halt its uranium conversion and enrichment activities, will meet in Berlin on Thursday to consider their next step.
(Chinadaily.com via agencies January 12, 2006)