Iran denounced the United States on Monday for contemplating possible nuclear strikes against Iranian targets and urged the United Nations to take urgent action against what it called a dangerous violation of international law.

Secretary of State Condoleezza Rice, leaves ABC studios, Sunday, April 30, 2006, in Washington. Iran's offer to let a watchdog agency inspect the country's nuclear facilities is a stalling tactic to avoid UN penalties that would further isolate Tehran, Secretary of State Condoleezza Rice said Sunday. [AP]

In a letter to UN Secretary-General Kofi Annan obtained by The Associated Press, Iran's UN Ambassador Javad Zarif called President Bush's refusal to rule out a U.S. nuclear strike on Iran and a similar follow-up statement by Secretary of State Condoleezza Rice "illegal and insolent threats."

Bush was asked on April 18 whether US options regarding Iran "include the possibility of a nuclear strike" if Tehran refuses to halt uranium enrichment. "All options are on the table," the president replied, but he stressed that the United States will continue to focus on diplomacy.

Iran insists it is legally entitled under the Nuclear Nonproliferation Treaty to enrich uranium to provide fuel for civilian power plants but the United States suspects its real aim is to produce nuclear weapons, a view backed by Britain and France.

Zarif said the use of "false pretexts" by senior US officials "to make public and illegal threats of resort to force against the Islamic Republic of Iran is continuing unabated in total contempt of international law and fundamental principles of the United Nations Charter."

The "US aggressive policy" of contemplating the possible use of nuclear weapons also violates the Nuclear Nonproliferation Treaty and other U.S. multilateral agreements, he said.

Zarif's letter made no mention of recent threats by Iran's President Mahmoud Ahmadinejad to wipe Israel "off the map."

Instead, the Iranian ambassador honed in on statements from U.S. officials, especially from Bush, which he said "defiantly articulate the United States policies and intentions on the resort to nuclear weapons."

Zarif said past UN failures to respond "to these illegal and inexcusable threats have emboldened senior United States officials to go further and even consider the use of nuclear weapons as an `option on the table.'"

In a brief statement responding to the letter, US Ambassador John Bolton said "if Iran wants to be treated differently, then Iran should stop pursuing nuclear weapons and give up terrorism."

The secretary-general had no immediate comment on the letter, said Marie Okabe, a U.N. spokeswoman.

After lengthy negotiations, the UN Security Council adopted a statement a month ago demanding that Iran stop enriching uranium. A new report Friday from the International Atomic Energy Agency, the U.N. nuclear watchdog, confirmed what the world already knew: Iran has refused to stop enriching uranium.

The United States, Britain and France immediately announced plans to introduce a new Security Council resolution this week which would make Iran's compliance with their demands mandatory. To intensify pressure, they want the resolution under Chapter 7 of the UN Charter which means it can be enforced through sanctions or military action.

China and Russia, the two other council members with veto power, oppose sanctions and military action and want the Iran nuclear issue resolved diplomatically, with the IAEA taking the lead, not the Security Council.

Iran's top nuclear negotiator, Ali Larijani, reiterated Monday that Tehran was "ready for any kind of negotiation to achieve our rights" and again called for Iran's dispute with the international community to be returned to the IAEA, rather than taken up by the Security Council.

He spoke on the eve of a meeting in Paris of political directors from the six countries that have been trying to find a diplomatic solution to the standoff ¡ª Britain, France, Germany, the United States, Russia and China.