NAM was founded in 1961 by mostly Third World leaders to try to avoid alignment with either the United States or the Soviet Union.
On the sidelines of the summit, scheduled for September 15-16, Ahmadinejad is due to hold talks with President Alyaksandr Lukashenka of Belarus. Both countries are facing international isolation.
Earlier today Ahmadinejad said he believed Iran's nuclear standoff with the West can be settled through "dialogue."
Speaking on a visit to the West African state of Senegal, the Iranian president said Tehran is ready for what he called "new conditions" regarding the nuclear issue, but gave no details.
He also said he does not believe the United Nations will impose sanctions over Iran's refusal to halt uranium enrichment.
(compiled from agency reports)