New York  - Iranian President Mahmoud Ahmadinejad condemned Israel for "genocide" against the Palestinians, defended his own election and insisted that Tehran would play a constructive role on the global stage, in a speech Wednesday to UN General Assembly.

He made no mention of Iran's nuclear activities, which dominated the talks of major powers attending the annual gathering at United Nations headquarters in New York.

Demonstrators rallied throughout the day outside the UN building to protest Ahmadinejad's visit.

Ahmadinejad caused outrage ahead of his visit by again denying the Holocaust during a rally in Tehran. On Wednesday, he said Palestinians have been "subject to genocide" and accused Israel of controlling global policy, including in the US and Europe, "to attain its racist ambitions."

Delegations from the United States and a host of other countries walked out of the General Assembly as he was speaking.

Ahmadinejad said Tehran wanted to play a bigger role on the global stage. He linked Iran's new ambitions to his own re-election this summer, which opposition candidate Mir-Hossein Moussavi said was rigged, and was followed by weeks of bloody unrest and repression in the country.

"Our nation has successfully gone through a glorious and fully democratic election, opening a new chapter for our country in the march toward national progress and enhanced international interactions," Ahmadinejad said.

Iran is ready "to engage into constructive process aimed at addressing the international concerns and challenges," he said.

While he rarely mentioned the United States by name, Ahmadinejad said Iran was "prepared to shake those hands which are honestly extended to us," a possible reference to US President Barack Obama's offer of direct talks with Tehran.

Iran earlier this month agreed to an October 1 meeting with global powers, including the US, but has said it considers the matter of its own nuclear activities closed for discussion.

Earlier Wednesday, Obama said that Iran could face further international sanctions if it did not engage in "serious negotiations" and come clean about its nuclear programme.

Western nations accuse Iran of wanting to build nuclear weapons. Iran has long insisted that its programme is intended for civilian nuclear energy.

Ahmadinejad called on the United States to pull back from intervention in all parts of the world.

"How can you talk about friendship and solidarity with other nations while you expand your military bases in different parts of the world, including in Latin America?" he said in a clear reference to the United States. (dpa)