Iran invited the United States on Monday to take part in building its nuclear program, aiming to allay Washington's fears that Tehran is developing a nuclear bomb.

Foreign Ministry spokesman Hamid Reza Asefi (search) said the United States should bid for contracts to build nuclear plants — though he did not say whether such bids would be allowed by Iran's supreme leader, Ayatollah Ali Khamenei, who has banned all official dealings between the two countries.

Any American bids would also have to get past U.S. sanctions, which bar most trade with Iran.

The invitation came as Russia, which is helping Tehran build its first nuclear plant, has been trying to mollify the United States over the Iranian nuclear program. At a summit Sunday with President Bush, President Vladimir Putin refused to halt aid, but he and Bush promised to work together to ensure Iran does not develop a nuclear weapon.

Russia's atomic minister said last week that Washington should join Moscow in building Iran's first plant, due to come on line at Bushehr (search) by the end of this year. Iran's foreign minister, Kamal Kharrazi (search), proposed Friday that Western countries help build the country's next plants.

Asefi took that offer a step further Monday, specifically inviting the United States.

"If the United States is really concerned, it can participate in the construction of nuclear power plants in our country," Asefi told a news conference.

Iran, which insists its nuclear program is for peaceful purposes, plans to build more nuclear plants but has not yet called for tenders. Bushehr will have a capacity of 1,000 megawatts, far short of the 6,000 megawatts that Iran seeks to produce from nuclear fuel by 2020.

The United States says oil-rich Iran does not need nuclear energy. Asefi dismissed that stance, saying that during the former regime of the pro-American shah, "the United States offered to build nuclear power plants for Iran, and it knew Iran had oil. What has happened so that they are taking a different line now?"

Iran's Islamic government and the United States have had no diplomatic relations since 1979, when Iranian militants after the toppling of the shah stormed the U.S. Embassy in Tehran and took its occupants hostage.

While reformers favor renewed contacts with Washington, supreme leader Khamenei has ruled out any formal dealings with the United States.

The United States accuses Iran of building a plant in the central city of Natanz to enrich uranium to produce bomb materials. The International Atomic Energy Agency (search) has visited the plant and will issue its report next month. Washington wants the agency to declare Iran in violation of the Nuclear Nonproliferation Treaty (search).

Meanwhile, Asefi also said Iran would announce the names of Al Qaeda members it has detained once they were identified.

"As soon as we learn about their true identities, we will announce it," Asefi said, adding that the detainees would eventually be returned to their countries of origin.

The United States has charged that Al Qaeda operatives in Iran played a role in the suicide attacks in Riyadh on May 12, which killed 26 bystanders. Kharrazi said Friday that the Al Qaeda detainees were arrested before the Riyadh bombings so they could not have been involved.

Asefi rejected as "Zionist-provoked propaganda" a U.S. court ruling that blamed Iran for the 1983 bombing of the U.S. Marines in Beirut, Lebanon, that killed 241 U.S. service personnel.

"It has no legal validity. Such courts get involved in political dealings rather than carrying out legal and judicial work," Asefi told reporters.

A U.S. district judge in Washington found Friday that the suicide truck bombing of the Marine barracks was carried out by the local militant group Hezbollah (search) with "massive material and technical support from the Iranian government." The court said Iran would have to pay damages to survivors and relatives.