Iranian President Mahmoud Ahmadinejad, during a speech to the U. N. General Assembly Thursday, harshly criticized the United States, Israel, and the West, accusing them of provoking wars, promoting global discord and spreading “totalitarianism.”

Mr. Ahmadinejad also blamed what he called “arrogant powers” of the West for causing worldwide recession and social inequalities.

While he spoke, delegations from the United States, France and and more than two dozen other nations walked out of the assembly.

As he has done in past U.N. speeches. Mr. Ahmadinejad advocated reform of the world body away from a power of Western axis. He said Western powers used the September 11, 2001 terrorism against the U.S. as a “pretext” to launch “attacks” on Iraq and Afghanistan.

Iran is at odds with European governments and the Obama administration over the controversial role of its nuclear program. Mr. Ahmadinejad often uses appearances on the international stage to demand a lessening of Western influence in directing global concerns.

The speech came after several hundred protesters rallied near the United Nations, voicing their displeasure over Mr. Ahmadinejad's presence at the General Assembly.

Mr. Ahmadinejad has stirred up controversy during past addresses to the U.N. He has denied the Holocaust and expressed doubt about the official version of the September 11, 2001 terrorist attacks — claims that prompted some diplomats to walk out during his speeches.

In an apparent effort to generate goodwill before this year's speech, Iran on Wednesday released two American hikers it had held for two years on suspicions of spying.

Shane Bauer and Josh Fattal were freed on a combined bail of $1 million in what Mr. Ahmadinejad called a “humanitarian gesture.” The two hikers spent Thursday with family who had flown to Oman to meet them.

Despite the release, U.S. President Barack Obama called for greater pressure on and isolation of Iran over its nuclear ambitions during his U.N. address on Wednesday.

Iran claims its nuclear program is for peaceful ends. The West fears Iran is trying to develop nuclear weapons.

Mr. Ahmadinejad's appearance was among a series of speeches on the second day of the 66th meeting of the General Assembly.

On the sidelines of the assembly, the head of the U.N.'s nuclear watchdog agency said that global use of nuclear power will continue to grow despite safety concerns. He spoke at a high-level meeting on the security of the world's nuclear power plants.

International Atomic Energy Agency Director-General Yukio Amano said that in the six months since Japan's Fukushima Daiichi nuclear power plant was crippled in a natural disaster, his agency has been working closely with the Japanese to contain the damage.