Iran has been hit by a series of sanctions from the Security Council over its refusal to halt its nuclear program, which some Western countries, in particular the United States, believe is geared towards developing atomic weapons.
The Iranian leader told the UN General Assembly in New York on Tuesday: "Among the ineffective bodies of the UN, the Security Council ranks first, as some of its members act as prosecutors, judges and executors."
He said the UN Security Council could not properly implement its commitments, and had lost international credibility.
"World War II victor countries have worked out a map of world domination... Some countries still behave like victors, treating other countries as losers who did not even take part in the war," Ahmadinejad said.
He said relations between veto-wielding member states and other countries that appear within their range of vision were reminiscent of those between master and slave in the Middle Ages.
He said the UN Security Council had politicized the issue of Iran's nuclear program, which he said should be considered closed, as Tehran recently intensified cooperation with the International Atomic Energy Agency, invited UN nuclear inspectors to visit a 40-MW heavy water reactor in Arak in late July, and gave its consent to answer questions on its nuclear program.
Ahmadinejad said the IAEA, the UN's nuclear watchdog, had since then stopped politicizing Iran's nuclear program.
The president said Iran would ignore further Security Council resolutions aiming to halt the country's nuclear program.
Iran has defied three consecutive UN resolutions against its nuclear program since last year. The six countries negotiating the dispute - permanent members of the UN Security Council plus Germany - have demanded that Tehran suspend all uranium enrichment before negotiating a solution to the dispute. Ahmadinejad announced in early April the start of uranium enrichment on an industrial scale.
He said he did not consider the Security Council to be a legitimate body authorized to impose sanctions against Iran, and said the measures had been introduced simply to hold back Iran's progress on any pretext.
"Some countries work out disarmament regulations, while simultaneously expanding their arsenals," the president said, mentioning the United States' plans to deploy missile defense elements in the Czech Republic and Poland.
"Europeans are faced with the menace of arms race, as some hooligan states feel at liberty to deploy anti-missile systems on their territory," Ahmadinejad said.
In response to a statement by U.S. President George Bush, who earlier commented on Iran's poor democratic record, he said that methods used by the governments of countries such as the U.S. to "rule the world" were "outdated, as they have a wrong vision. They lack a clear strategy to resolve different problems, including in Iraq, Afghanistan, the Palestinian territories and Lebanon."