TEHRAN, Iran - The U.N. chief got little satisfaction Sunday at the close of his trip to Tehran, snubbed by Iran's leader over international demands to stop enriching uranium and ignored in warnings not to incite hatred by questioning the Holocaust.

In a provocative move on the final day of Kofi Annan's two-day visit, Iran announced it would host a conference to examine what it called exaggerations about the Holocaust, during which more than 6 million Jews were killed by the Nazis. The move was sure to draw new international condemnation of Iran's stance on Jews. Hours after the announcement, Annan repeated his displeasure over an exhibition in Tehran of cartoons mocking the Holocaust that was opened as a response to Western caricatures of Prophet Muhammad.

“I think the tragedy of the Holocaust is an undeniable historical fact and we should really accept that fact and teach people what happened in World War II and ensure it is never repeated,” Annan told reporters.

He commented after a meeting with President Mahmoud Ahmadinejad, but the hard-line Iranian leader didn't accompany the U.N. chief to the news conference.