Iranian President Mahmoud Ahmadinejad has called for the U.S. to be removed from the International Atomic Energy Agency, in his opening speech at a nuclear disarmament conference in Tehran.

Mr. Ahmadinejad said Saturday countries that do not possess nuclear weapons should review the Nuclear Non-Proliferation Treaty, which aims to halt the spread of technologies that can be used to produce nuclear weapons. There was no immediate reaction from the U.S.

The Iranian government is hosting the two-day conference to counter the 47-nation nuclear security summit held earlier this week in Washington. Iran was not invited to the U.S. meeting.

The Iranian government said foreign ministers and other high-ranking officials from more than 60 countries were expected to attend the conference in Tehran.

The U.S. is pushing for a fourth round of United Nations sanctions over Iran's disputed nuclear program, but Iran insists the program is for peaceful, civilian purposes.