Iran's President Mahmoud Ahmadinejad warned Tuesday that an attack on his country's nuclear facilities could spark a war with "no limits," US media reported.

He also suggested that the Holocaust had been exaggerated as a "pretext for war," during a New York meeting with US media owners and editors.

"The United States doesn't understand what war looks like. When a war starts, it knows no limits," Ahmadinejad was quoted as saying in response to a question about any US-supported strike by Israel on Iran's nuclear facilities.

"The United States has never entered a serious war, and has never been victorious," the Atlantic magazine's online edition quoted him as saying.

"Do you think anyone will attack Iran to begin with?" he said, according to the monthly's website. "I really don't think so. The Zionist regime is a very small entity on the map, even to the point that it doesn't really factor into our equation."

The UN Security Council has imposed four rounds of sanctions against Iran over its nuclear program and the United States and its allies have called for stringent application of the measures.

The western powers accuse Iran of trying to develop a nuclear bomb. Ahmadinejad denies the charge. He is in New York for the United Nations General Assembly as well as the UN summit against poverty and hunger.

The Iranian leader said he was ready for nuclear talks with US President Barack Obama's administration, but said "the whole outlook has to shift," ABC News reported.

The UN sanctions had damaged the chances for an improvement in US-Iranian relations.

Ahmadinejad was again questioned about the killing of millions of Jews in Nazi death camps during World War II.

He described it as "a historical event used to create a pretext for war."

"The question is, why don't we allow this subject to be examined further.... It is incorrect to force only one view on the rest of the world," he was quoted as saying.

"We need to ask, where did this event occur, and why should the Palestinian people continue to suffer for it? I am not an anti-Semite. I am anti-Zionism," he said.

Ahmadinejad denied that Iran's opposition movement faced persecution. "Those individuals face no problems, no difficulties," he said. "They are all free in fact."

Ahmadinejad went on to give a chaotic speech at the UN summit on the Millennium Development Goals in which he blamed capitalism for the world's ills -- but no one except the controversial leader and his delegation were really sure what he said.

Ahmadinejad broke off one minute into his presentation to complain about the translation to the UN assembly presidency.

The president carried on again but at the end, the UN interpreters said they were only "reading from a translated text" and not following Ahmadinejad's comments.

The assembly hall was half empty, but Western delegations did not boycott the speech as they have done in previous years.

According to the translated text, Ahmadinejad called for fundamental reform of "the undemocratic and unjust" world order.

"Demanding liberal capitalism and transnational corporations have caused the suffering of countless women, men and children in so many countries," he was quoted as saying.

UN officials said that Farsi is not an official UN language and that Iran had not provided an official translator.