Iran's President Mahmoud Ahmadinejad shrugged off threats of a military strike on his country's nuclear facilities, showing defiance ahead of his final appearance at the UN General Assembly this week.

In previous years, the Iranian leader has regularly sparked United Nations walkouts over his comments on Israel, and Israel's UN ambassador again marched out when Ahmadinejad appeared at a meeting on the rule of law on Monday.

Ahmadinejad criticized Western powers for their sanctions on Iran over its nuclear program and for allowing filmmakers and cartoonists to lampoon the Prophet Mohammed in what he branded a "sacrilege" of Islam.

Before arriving at UN headquarters in New York, the Iranian leader dismissed the threats he said had been made by "the Zionists" against his country, which is at the center of an international showdown over its nuclear program.

"Uncultured Zionists that threaten the Iranian nation today are never counted and are never paid any attention in the equations of the Iranian nation," Ahmadinejad told Iranian expatriates in New York.

"The Iranian nation has never hesitated to defend itself against enemy threats and aggressions," Ahmadinejad was quoted as saying on his personal website.

"No bullying power has ever been successful in overcoming the Iranian nation."

At a meeting later with American media editors, Ahmadinejad said Iran reiterated that it does not take speculation of an Israeli military strike on Iran's nuclear facilities seriously.

The United States and its European allies accuse Iran of seeking to develop a nuclear bomb and the UN Security Council has imposed four rounds of sanctions against Iran.

Ahmadinejad's government insists it is seeking peaceful applications of nuclear power in energy generation and medical research.

"We believe the Zionists see themselves at a dead end and they want to find an adventure to get out of this dead end. While we are fully ready to defend ourselves, we do not take these threats seriously," the Iranian leader said.

Ahmadinejad will make his eighth and final appearance before the General Assembly on Wednesday. UN Secretary General Ban Ki-moon warned him about "the potentially harmful consequences of inflammatory rhetoric" in a meeting on Sunday.

The Iranian leader has in the past described Israel as a "tumor" to be removed surgically and said it should be "wiped off the map".

Iran and the tensions over its nuclear program are set to become a dominant topic at the weeklong UN assembly.

Britain, China, France, Germany, Russia and the United States -- which have sought to negotiate a settlement with Iran -- are to meet on Thursday to discuss the showdown.

Israel's Prime Minister Benjamin Netanyahu will address the assembly on the same day.

At the UN meeting on Monday, Ahmadinejad did not name the Western powers but attacked countries which he said "violate the basic rights and freedoms of other nations" and for defending Israel.

"Some members of the Security Council with veto rights have chosen silence with regard to the nuclear warheads of a fake regime while at the same time they impede scientific progress of other nations," he said.

Israel has an undeclared nuclear weapons program and has stepped up warnings against Iran in recent months.

"Ahmadinejad heads a state that is the most systematic violator of international law and the world's greatest sponsor of terrorism," said Israel's UN ambassador, Ron Prosor.

"It is shameful, disgraceful, and absurd that his voice was part of today's UN discussion on the rule of law."

The Iranian president also attacked the West over the recent furor stirred when American Christian conservatives made a film attacking Islam and a French magazine printed cartoons mocking the prophet.

"They themselves wrongly invoke the UN charter and misuse freedom of speech to justify their silence towards offending the sanctity of human communities and to divine prophets," he said. (AFP)