Iran’s ambassador in New York, Mohammad Javad Zarif, has forwarded a letter to the United Nations chief in which the regime condemned "American officials for their illegitimate and open threats to use force against the Islamic republic of Iran."
"These are in obvious contravention of international rules and the
principles of the United Nations," the letter was quoted as saying by the official news agency IRNA.
It said that "these rude threats have recently been publicised through some reports in US newspapers."
The letter noted a report in The New Yorker magazine last month which said US military planners had even looked into using nuclear 'bunker-busters' to strike Iran's atomic facilities.
"These (threats) have entered a new stage, with the refusal of US officials to deny these reports," the letter said, calling for "serious attention" as well as "quick and firm action" from the UN.
Concerns shared
Iran insists that its nuclear work is for peaceful purposes to produce power but uranium enrichment can also be extended to make the core of an atom bomb.
But on Friday a UN Security Council deadline for the work to stop expired without Iranian compliance.
Tehran wants is to continue enrichment and keep the case out of the Security Council, which unlike the International Atomic Energy Agency has enforcement powers.
Iran argues that fuel cycle work is its a right enshrined by the Non Proliferation Treaty and it remains defiant in the face of the US threats.
"The struggle of the Iranian people against the United States is like the struggle between Moses and the pharaoh," commented Mohsen Rezai, the right-wing secretary of Iran's top political arbitration body, the Expediency Council.
"For the Americans, it is not a nuclear issue but one of Iran progressing to become developed and powerful," he told the ISNA news agency.
The Iranian regime believes the crisis is merely an extension of US ambitions to see the ouster of Iran's ruling clerics.
Iran's top national security official Ali Larijani also argued that there
was "no sense" in the country returning to a suspension of enrichment.
"A suspension does not make any sense to us, because we do not think an atomic bomb can come out of a 164 centrifuge cascade," he was quoted as saying by the ISNA news agency.
Iran has installed 164 centrifuges at a pilot plant in Natanz, situated in the desert south of Tehran.
The regime argues it is so far only carrying out small-scale "research" work, and that it only wants to eventually make civilian reactor fuel.
In a show of support, about 2,000 Iranian workers demonstrated in favour of the program outside the former US embassy in central Tehran.
"Nuclear energy is our obvious right!" the workers chanted.
"With more work, sanctions will not affect us!"
Diplomatic drive
The complaint came as diplomats from the five permanent Council members and Germany are to meet in Paris on Tuesday and again at the foreign ministers level in New York on May 9.
The meetings follow an International Atomic Energy Agency
(IAEA) report confirming Iran has not complied with demands to freeze uranium enrichment.
Iran has been seeking to split Council members by balancing threats of tough reprisals -- such as ending IAEA inspections -- if the pressure mounts and some concessions if it eases.
Russia and China are for the time being opposed to any sanctions, or a resolution invoking the UN Charter's Chapter 7 -- a reference which would open the door to political and economic sanctions and even, as a last resort, military action.
The United States and Europe are hoping Russia and China will
agree to a robust resolution that legally obliges Iran to halt the nuclear work.
US President George W Bush telephoned his Russian counterpart Vladimir Putin to discuss ways to block Iran from obtaining nuclear weapons, the White House said.
Mr Bush "stressed the importance of preventing Iran from obtaining nuclear weapons" including efforts currently under way in the UN Security Council.
White House spokesman Scott McClellan said the two leaders
"committed to remaining in close contact on this important
priority".