"The rights and dignity of the American people are also being sacrificed for the selfish desires of those holding power," he added.
"The countries that feel threatened ... should prepare for defence, and even counterattack"
Adolfo Talpalar, Stockholm, Sweden
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Ahmadinejad also used his speech to say the issue of Iran's nuclear programme was "closed" and should be handled by the UN nuclear watchdog.
Without specifically naming them, he accused Washington and its allies of bullying Iran - which they say is trying to develop nuclear weapons - and putting pressure on the International Atomic Energy Agency (IAEA) for their own purposes.
Ahmadinejad said: "Fortunately, the IAEA has recently tried to regain its legal role as supporter of the rights of its members while supervising nuclear activities.
"Today, because of the resistance of the Iranian nation, the issue is back to the agency, and I officially announce that in our opinion the nuclear issue of Iran is now closed and has turned into an ordinary agency matter," he said, adding Iran was prepared to have "constructive talks with all parties".
Addressing the General Assembly earlier in the session George Bush, the US president, made little reference to Iran.
Instead, both Angela Merkel, the German chancellor, and Nicolas Sarkozy, the French president, sought to increase pressure on the Islamic republic, saying they would not accept a nuclear-armed Iran.
Merkel, said: "if Iran were to acquire the nuclear bomb, the consequences would be disastrous."
Sarkozy told the session: "Iran is entitled to nuclear power for civilian purposes, but to allow Iran to acquire nuclear weapon is an unacceptable risk to the stability of the region and the stability of the world."
Iraq invasion criticised
Ahmadinejad also used his speech to criticise the US-led invasion of Iraq, which he said was "occupied under the pretext of overthrowing the dictator and the existence of weapons of mass destruction".
He criticised the UN Security Council for being an exclusive club answerable to no one, saying that those in power were in the "sunset of their times".
He also voiced support for the Palestinians, saying: "The Palestinian people have been displaced or are under heavy military pressure, economic siege or are incarcerated under abhorrent conditions.
"The occupiers are protected and praised, while the innocent Palestinians are subjected to political, military and propaganda onslaughts."
Neither the US nor the Israeli delegation stayed to listen to the Iranian leader's speech.