Iran's Foreign Ministry is downplaying a threat by President Mahmoud Ahmadinejad to pull out of the Nuclear Non-Proliferation Treaty.

A spokesman, Hamid Reza Asefi, says Iran is committed to the provisions of the treaty, but cannot accept its use as a political tool. On Saturday, Mr. Ahmadinejad said he might pull out of the treaty to end growing international pressure on Iran to end its nuclear program.

U.S. Secretary of State Condoleezza Rice says such a move would further deepen Iran's isolation. Rice said Sunday there is a coalition of countries, including all members of the U.N. Security Council, determined to prevent Iran from developing nuclear weapons.

She added the U.S. is dedicated to a diplomatic approach but has taken no options off the table when it comes to dealing with Iran, including military action.

Western nations, led by the United States, accuse Iran of secretly developing nuclear weapons, a charge Tehran denies.