United Nations weapons inspectors are in Tehran for meetings with senior Iranian officials in an effort to determine whether the Islamic republic is seeking to develop nuclear weapons.
The talks are being described as critical with an October 31 deadline approaching for Iran to prove it is not engaged in the production of nuclear weapons.
Inspectors with the International Atomic Energy Agency are in Tehran discussing, among other things, Iran's uranium enrichment program, which could be used to produce nuclear weapons. Iran has also been testing centrifuges used to enrich uranium.
Iran insists its nuclear program is solely for the peaceful production of electricity, but Washington has said it believes Tehran may be using the program as a cover to produce atomic weapons.
The IAEA has said the October 31 deadline is non-negotiable and that unless Tehran is able to allay international concerns over its nuclear program it could face stiff economic and diplomatic sanctions from the United Nations Security Council.
Iran has said it intends to cooperate with the inspectors but not without its right to enrich uranium being guaranteed.