The October 1 meeting with the US, China, Russia, Germany, France and Britain is to be the first of its kind since Barack Obama, the US president, took office.
Ahmadinejad also said Iran is interested in buying enriched uranium for its nuclear power plants.
His comments came a day after Manouchehr Mottaki, the Iranian foreign minister, said Tehran would push for international nuclear disarmament.
Talks with Japan
During a meeting on the sidelines of the General Assembly, Mottaki told Katsuya Okada, his Japanese counterpart, Iran wants to co-operate with Japan in working to abolish nuclear weapons.
Japan is the only country to have suffered a nuclear attack when its cities of Hiroshima and Nagasaki were bombed by the US during the second world war.
Mottaki also said Iran would push for expanded opportunities for all countries - including his own - to use nuclear power for peaceful purposes.
He told Okada that Tehran had no intention of acquiring nuclear weapons and that the age of nuclear weapons was over, Japanese officials said.
Okada said it was a pity suspicion hung over Iran's nuclear activities and urged Mottaki to hold frank discussions with the
Although Hillary Clinton, the US secretary of state, has said the discussions must address the nuclear issue during the forthcoming summit, Iran insists its nuclear activities will not be on the agenda.