UNITED NATIONS (AP) — A nuclear conference at the United Nations next week could provide Iranian President Mahmoud Ahmadinejad with an opportunity to lobby against a fourth round of U.N. sanctions on his nation.

Ahmadinejad has applied for a U.S. visa to attend next month's conference to review the Nuclear Nonproliferation Treaty at U.N. headquarters in New York, U.S. Ambassador Susan Rice said Wednesday.

The conference opens Monday and lasts nearly until the end of May.

State Department spokesman P.J. Crowley said applications for the Iranian delegation, including Ahmadinejad, had been given to the U.S. Embassy in Bern, Switzerland, earlier Wednesday and were under review.