Iranian President Mahmoud Ahmadinejad unleashed a blistering attack Monday against Israel and the United States, calling the Jewish state "racist" and lashing out at Americans for their support.
Ahmadinejad called Israel the "most cruel and racist regime."
He followed by blaming the United States, Europe and Israel for the world's financial crisis, but shrugged off a question later about whether the U.S. not attending the conference would further hurt relations between the two countries.
"We should listen to all and choose the best of the ideas," Ahmadinejad said at a news confercence after his speech.
Excerpts From Ahmadinejad's Speech at U.N.
Protesters stormed the stage when Ahmadinejad began speaking and several Western delegates walked out of the room after the Iranian president said Israel was created on the "pretext of Jewish suffering" from World War II.
Among the diplomats seen leaving the room were envoys from Britain, France and Canada, who had all previosuly threatened to stand up and leave if the Iranian president made anti-Semitic statements, the Times of London reported.
President Obama spokesman Robert Gibbs called Ahmadinejad's remarks, "hateful rhetoric."
A wigged protester shouting "Racist! racist!" threw a soft red object at Ahmadinejad, hitting the podium and interrupting his speech. He was detained and escorted vast conference room at the Palais des Nations by guards.
Later, other protesters shouted down from the balcony as the Iranian president, who has often called for Israel to be wiped from the map, carried on his speech.
"We did it because it's all a farce," Joelle Jakubowicz, a protester who represented the union of Jewish Students in France, told the Guardian. "You can't fight racism if you are racist yourself."
Ahmadinejad said just because a country has nuclear technology, it doesn't mean they are going to use to build a nuclear bomb. Instead, he insisted it should be used to create clean energy, and protect the environment.
Meanwhile, U.N. Secretary-General Ban Ki-moon urged the world Monday to rally against the threat that intolerance could rise as a result of the economic crisis, saying "the time is now" to stamp out racism.
Ban, opening the global body's first racism conference in eight years, said racism including anti-Semitism and Islamophobia needed to be tackled.
"I fear that today's economic crisis, if not handled properly, could evolve into a full-scale political crisis marked by social unrest, weakened governments and angry publics who have lost faith in their leaders and their own future," the U.N. chief said.
"In such circumstances, the consequences for communities already victimized by prejudice or exclusion could be frightening."
He also said he regretted the absence of the United States and eight other Western nations that have pulled out because of fears Muslim nations will dominate the conference with calls for to denounce Israel and for a global ban on criticizing Islam.
"There comes a time to reaffirm our faith in fundamental human rights and the dignity and worth of us all," Ban told the gathering of thousands of ministers, diplomats and dignitaries at the U.N.'s European headquarters in Geneva.
President Obama's administration announced Saturday it would boycott the weeklong meeting because it makes reference to a declaration made in 2001 at the global body's first racism conference in Durban, South Africa.
That document was agreed after the United States and Israel walked out over attempts to liken Zionism — the movement to establish a Jewish state in the Holy Land — to racism.
Organizers have sought to steer clear of the controversies that marred the Durban meeting, but have run into many of the same contentious issues. Australia, Canada, Germany, Israel, Italy, Netherlands, New Zealand and Poland are also not participating, while Iran's hardline President Mahmoud Ahmadinejad is scheduled to take the floor later Monday.
The major sticking points in the draft final declaration prepared for the current meeting concern its implied criticism of Israel and an attempt by Muslim governments to ban all criticism of Islam, Sharia law, the prophet Muhammad and other tenets of their faith.
Obama, speaking in Trinidad on Sunday after attending the Summit of the Americas, said: "I would love to be involved in a useful conference that addressed continuing issues of racism and discrimination around the globe."
But he said the language of the U.N.'s draft declaration risked a reprise of Durban, during which "folks expressed antagonism toward Israel in ways that were often times completely hypocritical and counterproductive."
"We expressed in the run-up to this conference our concerns that if you adopted all of the language from 2001, that's not something we can sign up for," Obama said.
Ban said no society — rich or poor, large or small — is immune to the dangers of racism, which he called a "denial of human rights, pure and simple."
Addressing intolerance in its various forms, Ban said racism "may be institutionalized, as the Holocaust will always remind us," but that it may manifest itself in more subtle forms through the "hatred of a particular people or a class — as anti-Semitism, for example, or the newer Islamophobia."
Many Muslim nations want curbs to free speech to prevent insults to Islam they claim have proliferated since the terrorist attacks in the United States on Sept. 11, 2001. They cite the 2005 cartoons of Muhammad published by a Danish newspaper that sparked riots in the Muslim world, and allegations that authorities in the West have targeted innocent Muslims through anti-terror and other police action.
Those demands had been largely resisted by the United States and other Western nations, some of whom are participating in the conference.
Ban steered clear of the issue of a global ban on religious defamation, as demanded by Muslim nations, but urged action against a "new politics of xenophobia" that is on the rise and could become dramatically worse as a result of new technologies that proliferate hatred.
The Associated Press contributed to this report.