U.N. Secretary-General Kofi Annan asked former Iranian President Mohammad Khatami on Tuesday to help foster dialogue with the United States, as the moderate cleric wound down an unprecedented U.S. tour, the United Nations said.

Annan and Khatami kissed each other on the cheek three times and chatted amiably before the private meeting began. It came near the end of Khatami's trip, which has taken him to Boston, Chicago and Washington.

"The secretary-general expressed his wish to see more dialogue between the United States and Iran on different levels and said he hoped President Khatami would be useful in that regard," U.N. spokesman Stephane Dujarric said.

Khatami brushed past reporters on his way out of the U.N., smiling and pointing to his watch as he sped out the door to a waiting motorcade.

Khatami's five-city tour of the United States has angered some conservatives in Congress, and some influential Iranian exiles in the United States.

The two-week tour was the result of an invitation from the U.N. for Khatami could attend a meeting of the Alliance of Civilizations, a U.N.-sponsored group that promotes understanding between Western and Islamic states.

Khatami is a founding member of the alliance.

Officials at Iran's U.N. Mission refused to say when he was leaving, though diplomats said it would be either late Tuesday or Wednesday.