The Associated Press
Ban says the Iranian leader used his speech "to accuse, divide and even incite," directly opposing the aim of the meeting.
Ahmadinejad used the platform Monday to accuse Israel of being a "most cruel and racist regime."
His speech, which was repeatedly disrupted by protesters, sparked a walkout by angry Western diplomats.
The incident overshadows the weeklong effort to forge global unity in the fight against racism.
