Delegations from about a dozen countries, including Canada, walked out of the UN General Assembly as Iranian President Mahmoud Ahmadinejad delivered a fiercely anti-American speech Thursday.

The Canadian delegation was the first to walk out, just as Ahmadinejad entered the room at the UN in New York City, reports CBC's David Common. 

U.S. and European delegates, as well as others, walked out of the chamber soon after.

Ahmadinejad attacked the United States for its history of slavery, causing two world wars, using a nuclear bomb against "defenceless people," and imposing and supporting military dictatorships and totalitarian regimes on Asian, African and Latin American nations.

'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.'—Mark Kornblau, spokesman, U.S. Mission to the United Nations

Ahmadinejad's speech temporarily took the spotlight off the Palestinians' bid for statehood. President Mahmoud Abbas is expected to formally deliver a letter requesting membership on Friday when his turn comes to speak to the General Assembly.

Mark Kornblau, spokesman for the U.S. Mission to the United Nations, said: "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."

The Iranian leader accused the U.S. of threatening to place sanctions on anyone who questions the Holocaust and the Sept. 11, 2001, attacks.

Ahmadinejad accused some unidentified European countries of still using the Holocaust "as the excuse to pay fine or ransom to the Zionists." He also said any question about the foundation of Zionism is condemned by the U.S. "as an unforgivable sin."

When the idea of an independent fact-finding investigation of "the hidden elements" involved in the Sept. 11 attacks was raised last year, he said, "my country and myself came under pressure and threat by the government of the United States."

"Instead of assigning a fact-finding team, they killed the main perpetrator and threw his body into the sea," Ahmadinejad said, referring to the U.S. military's killing of al-Qaida leader Osama bin Laden in early May.

At the entrance to Dag Hammarskjold Plaza across from the UN, a same-sex "wedding" was staged mocking the alliance of Syria and Iran. A protester posing as ousted Libyan leader Moammar Gadhafi presided over the ceremony, with yellow cake served to onlookers, representing the uranium used to make nuclear weapons.

The pavement of the plaza was covered with huge banners, one of which read: "Down With the Islamic Republic of Iran." Children stomped on a poster of Ahmadinejad.

Palestinian state still a goal of Abbas

Also on Thursday, Palestinian officials brushed aside a promised U.S. veto and pressure to abandon their bid for UN membership, saying they were determined to take their case to the Security Council and realize a goal unfulfilled by decades of negotiations.

Senior aides to Abbas said the Palestinians would not accept political delays in their membership bid, but acknowledged that final UN action might not be taken for months or even longer.

The issue has dominated the annual meeting of the world body as the diplomatic world swirled with speculation about what deals might be in the works.

The United States, insisting that Palestinian statehood depends first on peace with Israel, has vowed to veto the Palestinian measure should it win the needed nine of 15 Security Council votes.

Teams of envoys from the United States, the European Union and France were engaged in frenzied, last-minute efforts to persuade Abbas to return to the negotiating table and make do with something less than full UN membership.

Obama reiterates opposition to statehood bid

U.S. President Barack Obama and Abbas met for more than 45 minutes Wednesday evening.

The White House wouldn't say whether Obama directly asked the Palestinian leader to abandon his plans to pursue full UN membership, saying only that he reiterated his opposition to the statehood bid and the U.S. intention to issue a veto.

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U.S. President Barack Obama, right, meets with Palestinian President Mahmoud Abbas during the UN General Assembly in New York on Wednesday. ((Pablo Martinez Monsivais/Associated Press))

A frustrated Obama told world leaders during his Wednesday UN speech that "there are no shortcuts" to peace.

So far there was no indication that Abbas was ready for compromise despite intense pressure, but his aides said they were not setting deadlines for the Security Council to consider the application. And they left the door open for a Plan-B request to the General Assembly for an upgrade of their current status as a permanent observer to a non-member observer state.

That option is seen as the lesser of two evils by the U.S. and others seeking to steer them clear from the Security Council for now.

"This is an option that is open to us ... starting tomorrow, if we chose to do so, but President Abbas does not want anybody to suspect a lack of seriousness if we address the two councils at the same time," Palestinian negotiator and senior Abbas adviser Nabeel Shaath told reporters. "So he will give some time to the Security Council to consider first our full membership request before heading to the General Assembly."

"We do not have a time limit," said Shaath. Nevertheless, he said, "This is a moment of truth."

Israel, meanwhile, is urging the Palestinian government to return to the negotiating table rather than seek UN recognition.

Mark Regev, spokesman for the Israeli government, said a successful bid at the UN would only give Palestinians a "piece of paper."

Regev said true statehood will only be achieved through negotiation.

"My prime minister is in New York; their president is in New York. Let's meet today. And let's restart the peace process."

With files from CBC News