The head of the U.N. nuclear watchdog agency arrived in Tehran Friday to begin inspecting nuclear facilities which Washington says could be used to produce nuclear weapons, an Iranian atomic energy official said. Mohamed ElBaradei, director-general of the U.N.'s International Atomic Energy Agency, was due to visit two plants being built near the towns of Natanz and Arak and to meet President Mohammad Khatami.

Iran, branded by the United States part of the "axis of evil" along with Iraq and North Korea, has repeatedly said its nuclear program is intended purely to meet the growing energy demands of its 65 million people.

But Washington fears the two plants and a reactor being built with Russian help at Bushehr could be part of a nuclear weapons program and asks why Iran, OPEC's second biggest oil producer and with the world's second biggest gas reserves, needs nuclear power.

"I have been promised that they would like to be fully transparent and that they would like to demonstrate their nuclear program is fully dedicated to peaceful purposes," ElBaradei told Reuters in an interview Tuesday.

He said he would encourage Tehran, already a signatory to the nuclear Non-Proliferation Treaty, to sign the so-called Additional Protocol. This obliges signatories to open up all nuclear facilities to intrusive inspections by the U.N. agency.

U.S. concern over Tehran's nuclear program rose this month after Khatami announced Iran had uranium ore reserves and had begun mining operations in the Savand area, 125 miles from the central city of Yazd.

The head of Iran's atomic energy agency then outlined an ambitious nuclear energy program and said Iran was poised to begin processing uranium.

Washington then sent Undersecretary of State John Bolton, the administration's top arms control and non-proliferation official, to Moscow where he is due to hold talks from Sunday meant to keep Tehran from achieving full nuclear capability.

The United States has so far had little success in its efforts to stop Moscow providing equipment, fuel and technical expertise in the construction of the Bushehr plant.

U.S. officials said Iran's recent announcements have "torn to shreds" Russian assurances that Moscow would provide the nuclear fuel for the Iranian facility and then take all the spent fuel back for reprocessing.

PHOTO CAPTION

Director General of the International Atomic Energy Commission, Dr. Mohamed ElBaradei, addresses the United Nations Security Council on the status of inspections in Iraq at U.N. headquarters in New York, February 14, 2003. ElBaradei and Chief U.N. Weapons Inspector Dr. hans Blix briefed the members of the Council on the status of the U.N. weapons inspections in Iraq in the open high-level Security Council meeting. REUTERS/Peter Morg