TEHRAN, Iran — Iran notched up the brinksmanship over its disputed nuclear program Monday, abruptly postponing talks with Moscow on a plan to enrich Tehran's uranium on Russian territory to allay fears it is building an atomic weapon.
Diplomats in Europe said Iran had started small-scale enrichment of uranium, a process that can produce fuel for an atomic bomb.
"Uranium gas has been fed into three machines," said a senior diplomat in Vienna, Austria, who spoke on condition of anonymity because he was not authorized to comment on the matter. Another diplomat confirmed that limited enrichment had begun at Iran's Natanz site.
State-run Iranian television later reported that Alaeddin Boroujerdi, head of the national security and foreign relations committee in parliament, said the country had begun peaceful nuclear enrichment activities Monday. Boroujerdi said inspectors from the Vienna-based International Atomic Energy Agency were present.
A new poll has found that a majority of Americans said the United States should take diplomatic action to prevent Iran from acquiring a nuclear weapon. Americans also fear the United States will be too quick to resort to a military attack, a CNN/USA Today/Gallup poll found.
Sixty-eight percent of the adults surveyed said the United States should use economic and diplomatic efforts to get Iran to shut down its nuclear program, compared with 9 percent who said the United States should take military action now, the poll found.
If diplomacy fails, 49 percent of the respondents said the United States should still refrain from immediate military action, compared with 40 percent who said the United States should go to war. The poll of 1,000 adults was conducted from Feb. 9 to 12 and has a margin of error of plus or minus three percentage points.
The Iranian talks with Russia had been slated for Thursday but were postponed indefinitely because of the "new situation," said Iranian presidential spokesman Gholamhossein Elham. He was referring to the IAEA's decision this month to report Iran to the U.N. Security Council because of uncertainty over its nuclear intentions.
Iran maintains its nuclear program is designed solely to generate electricity, but the United States and some U.S. allies claim the program is a cover for producing an atomic bomb.
Moscow had proposed that Iran ship its uranium to Russia, where it would be enriched to a level suitable for nuclear reactors. It would then be returned to Iran for use at the Russian-built Bushehr plant, which is due to begin operating this year.
The plan, backed by the United States and the European Union, was an attempt to avoid international objections to Iranian uranium enrichment by providing oversight so no weapons would be made. Iran had said the plan did not fulfill its requirements but was worth pursuing.
Despite resumption of enrichment, uranium gas must be fed into hundreds of centrifuges to produce significant amounts of enriched uranium, which — depending on the degree of processing — can be used for civilian nuclear reactors or warheads.
Iran is years away from running the 50,000 centrifuges it says it wants to operate as a source of fuel for its Bushehr plant.
But even small-scale enrichment is significant because it represents symbolic determination by Tehran to go ahead with a technology that most nations want it to give up because of fears of misuse.
In Washington, White House press secretary Scott McClellan said Iran's restarting of enrichment shows its "continued defiance of the world."
"The regime in Iran knows what it needs to do," he said. "So far, they're continuing to choose defiance and confrontation over cooperation and diplomacy."
Also Monday, Tehran issued its third veiled threat in as many days to withdraw from the Nuclear Nonproliferation Treaty.
If the international community does not agree to Iran's right to enrich uranium under the NPT, "there is no reason to continue our current nuclear policy while we are deprived of the positive aspects of the treaty," said a spokesman for President Mahmoud Ahmadinejad.
U.N. Secretary-General Kofi Annan said the NPT allows Iran to develop nuclear energy but not weapons.
"I think the rules are very clear, Iran can develop peaceful ... uses of nuclear energy but not (a) nuclear bomb, and this is what the whole debate is about," Annan told CNN.
North Korea — the world's other major proliferation concern — quit the treaty in January 2003, just a few months before U.S. officials announced that the North had told them it had nuclear weapons and may test, export or use them depending on U.S. actions.
Iran had warned it would resume large-scale enrichment of uranium after it was reported Feb. 4 to the U.N. Security Council by the 35-nation IAEA board. The resolution indirectly linked the referral to breaches of the treaty and concerns that Tehran's activities represented a threat to world peace.
The IAEA is to issue a report on Iran at its March meeting. After that, the Security Council is expected to consider taking steps against the country.
German officials expressed disappointment the Moscow meetings were postponed.
Canceling or postponing the talks means the time before the March IAEA meeting "would not be used as effectively as is possible and necessary to push on toward a diplomatic solution," German Foreign Ministry spokesman Jens Ploetner said.
On behalf of the European Union, Germany, Britain and France had conducted lengthy but essentially fruitless discussions with the Iranians hoping promises of civilian nuclear technology and other economic incentives would lure Iran away from the nuclear path that could produce weapons.
Much of the surveillance equipment and seals from Iran's nascent uranium enrichment facilities at Natanz have been removed by the Iranians in the month since they announced they would resume limited activities there.
Without the seals and surveillance equipment — and with Iran's recent decision to end the agency's rights to in-depth nuclear inspections at short notice — the IAEA has few means to monitor Tehran's enrichment efforts.
It also has crippled the agency's efforts to look for secret sites and experiments that could be linked to nuclear arms.
Contributing: Bloomberg News