U.N. nuclear inspectors and senior Iranian officials have begun meetings in Tehran regarding Iran's nuclear program.

With a deadline of October 31 for Iran to prove it is not secretly developing atomic weapons, Iranian officials met in Tehran with a team of inspectors from the International Atomic Energy Agency.

Their talks have been described as decisive, and could determine whether the Islamic republic will face stiff economic and diplomatic sanctions from the U.N. Security Council, if it fails to allay international concerns.

Washington has accused Iran of diverting its nuclear resources to a secret weapons program. Iran has vehemently and repeatedly denied the charge, saying its 20-year program is for the peaceful production of electricity.

But since August, inspectors have twice discovered trace amounts of highly enriched uranium in Iran. Tehran officials admitted that, but said the uranium must have come from companies that shipped equipment to Iran.

The latest round of discussions and inspections are expected to center on Iran's uranium-enrichment program. Such a program could be used in the development of nuclear weapons.

In addition to the October 31 deadline, the IAEA also wants Iran to ratify and implement an additional protocol to the nuclear Non-Proliferation Treaty, which allows for tougher and unannounced inspections.