UNITED NATIONS — U.S. diplomats walked out of the U.N. General Assembly Thursday as Iran’s President Mahmoud Ahmadinejad delivered a fiercely anti-American speech, attacking the U.S. as an “arrogant power” ruled by greed.

More than a dozen diplomats from other countries, including France, left the chamber soon after. Ahmadinejad also attacked the United States for its history of slavery, accused it of causing two world wars and using a nuclear bomb against “defenseless people.” He further said Washington was guilty of imposing and supporting military dictatorships and totalitarian regimes in Asia, Africa and Latin America.

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.”