The Minister of Foreign Affairs of Iran, Manouchehr Mottaki, delivers his speech during the fourth UN Human Rights Council at the European headquarters of the United Nations in Geneva, Switzerland, Monday, March 12, 2007. [AP]

GENEVA - Iran's foreign minister accused Israel and the United States of posing the main threats to the security of the Middle East. The US and Israeli delegations walked out during the speech Tuesday.

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The comments from Foreign Minister Manouchehr Mottaki come as Iran - under sanctions for its refusal to stop uranium enrichment - faces increasing pressure to open its nuclear program to greater scrutiny. The United States and some allies accuse Iran of using the atomic program as a pretext to build weapons; Iran says its intentions are peaceful.

Mottaki told the world's top disarmament forum that Israel was the only country in the region that refuses to accede to the Nuclear Non-Proliferation Treaty, and said Prime Minister Ehud Olmert last year acknowledged that his country had nuclear weapons - which Olmert denies doing.

A nuclear-armed Israel poses "a uniquely grave threat to regional and international peace and security and requires to be seriously dealt with by the international community taking practical measures," Mottaki told the 65-nation Conference on Disarmament.

Mottaki did not use the word Israel, but referred to the country as "the Zionist regime," which he said had "a long and dark record of crimes and atrocities such as occupation, aggression, militarism, state terrorism, crimes against humanity and apartheid."

Israeli Ambassador Yitzhak Levanon said his delegation found the speech insulting and decided to leave: "Everybody noticed that we left because we made a small noise, showing everybody that we disagree with his remarks."

They were followed by the US delegation and the American mission said in a statement that Mottaki's "outrageous and divisive comments are not useful."

"He went too far," Levanon told The Associated Press, adding that it was "a blatant insult" to the conference to stray in such a way from the disarmament issues the body is supposed to consider.

"It seems the Iranians are under international pressure and this is what explains their undiplomatic behavior," Levanon said.

Mottaki noted the growing pressure being exerted on Iran in the UN Security Council, with a series of sanctions aimed at forcing the country to suspend uranium enrichment.

"It is surprising that while no practical step is taken to contain the real source of nuclear danger in the Middle East, my country is under tremendous pressure to renounce its inalienable right for peaceful use of nuclear energy," Mottaki said.

The other threat to the Middle East comes from the United States, which he said invaded Iraq on the pretext of eliminating weapons of mass destruction and bringing more security to the region.

"After years of searching for weapons of mass destruction in Iraq it is obvious the preparation for the attack on Iraq was based on false or, in fact, forged information," Mottaki said.

For the rest, he said, "one can easily judge if there is more security or insecurity in the region as the result of such a huge military operation. Those who created such a situation in Iraq cannot disregard their responsibility."

The conference is intended to negotiate disarmament treaties, but deep divisions over what weapons should be tackled next have left it little more than a forum for speeches since it created the nuclear test-ban treaty in 1996.