The United States on Thursday led a mass walkout of the UN General Assembly as Iran's President Mahmoud Ahmadinejad launched an outspoken attack on Western nations.
The Iranian leader again cast doubt on the origins of the Holocaust and the September 11, 2001 attacks and criticized the United States for killing Al-Qaeda leader Osama bin Laden rather than bringing him to trial.
European countries use the Holocaust as an excuse to pay "ransom to the Zionists," he said. The "diabolical" aims of the West are the cause of wars and the financial crisis, Ahmadinejad stormed.
In a repeat of walkouts at the United Nations and other international events in recent years, a US diplomat monitoring the speech in the UN General Assembly left halfway through the 20-minute discourse.
The 27 European Union nations then followed in a coordinated protest move.
"Mr Ahmadinejad had a chance to address his own people's aspirations for freedom and dignity, but instead he again turned to abhorrent anti-Semitic slurs and despicable conspiracy theories," said US mission spokesman Mark Kornblau.
A French spokesman called Ahmadinejad's attacks "unacceptable" in a message sent on Twitter, and the German delegation said it was protesting the "crude, anti-American, anti-Israeli and anti-West tirade by the Iranian president."
Earlier Ahmadinejad had offered to halt Iran's production of low-enriched uranium -- which can be a stepping stone to producing atomic weapons -- if the West supplied Tehran with the material in return.
But he failed to mention either the nuclear crisis with the West or the Palestinians bid to join the UN as a full member state in his speech.
Iran, accused by Western nations of seeking to develop a nuclear weapon, is under four sets of UN sanctions for refusing for years to bow to international demands to rein in uranium enrichment.
"If they give us the 20 percent enriched uranium this very week, we will cease the domestic enrichment of uranium of up to 20 percent this very week. We only want the 20 percent enrichment for our domestic consumption," Ahmadinejad told The New York Times.
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The European Union also offered to resume the sputtering talks with Iran over its suspect nuclear program which broke down in January.
But the invitation seemed to cut little ice with Ahmadinejad.
Some European countries "still use the Holocaust, after six decades, as the excuse to pay fine or ransom to the Zionists," he told the assembly.
The United States considered Zionism as "sacred" while they "allow sacrileges and insult" against other religions, he railed.
And on the Palestinian issue, he referred only to the imposition of "60 years of war, homelessness, terror and mass murder on the Palestinian people and on countries in the region."
The EU's foreign policy chief Catherine Ashton however has offered to resume talks between Iran and the so-called P5+1 group of Britain, China, France, Russia, the United States and Germany.
The European Union is "ready to resume talks with Iran on building confidence in the nature of its nuclear program, on the understanding that Iran is ready to enter into meaningful talks without pre-conditions," spokeswoman Maja Kocijancic said.
Britain's Prime Minister David Cameron, who stepped up to the podium after Ahmadinejad, sharply criticized the Iranian leader.
"He didn't remind us that he runs a country where they may have elections of a sort but they also repress freedom of speech, do everything they can to avoid the accountability of a free media, violently prevent demonstrations and detain and torture those who argue for a better future," Cameron said.
Across the street from the sprawling United Nations complex, behind steel security barriers, about 400 people rallied to protest the Iranian regime under the banner of the opposition People's Mujahedeen Organization of Iran.
"While Ahmadinejad is getting the podium at the world's biggest party, the Iranian people are being suppressed," said organizer Ali Safavi.
The rally was addressed by guest speaker John Bolton, the mustachioed, hawkish US ambassador to the United Nations under former US president George W. Bush.
He spoke of his scorn for the world body, branded Ahmadinejad "the world's central banker of terrorism," and proposed an undiplomatic solution.
"I believe it should be the declared policy of the United States to overthrow the regime," he said to cheers.