The United States said Tuesday it will conduct "a full investigation" along with the Iraqi government of the reported disappearance from Iraq's nuclear facilities of high-precision equipment that could be used to make nuclear weapons (search).

In a letter to the Security Council on Monday, U.N. nuclear chief Mohamed ElBaradei (search) said satellite photos and follow-up investigations show "widespread and apparently systematic dismantlement" at sites related to Iraq's nuclear program which had been subject to monitoring by the International Atomic Energy Agency (search).

While some industrial material that Iraq sent overseas has been located in other countries, he said no high-precision items including milling machines and electron beam welders that can be used commercially and in nuclear weapons production have been found.

Since the missing equipment and material "may be of proliferation significance," he asked any country with information about the items to inform the International Atomic Energy Agency.

U.S. deputy ambassador Anne Patterson said the U.S. Mission to the United Nations had not yet received ElBaradei's letter.

"We're anxious to see what he has to say, and we'll do a full investigation," she said, then quickly added: "I mean we'll work with the government of Iraq on a full investigation."

IAEA spokeswoman Melissa Fleming said the agency's assumption is that "this was organized looting" by people trying "to make a buck" and sell equipment and material to the highest bidder. Looting was rampant in the first days after the U.S.-led invasion of Iraq toppled the Saddam Hussein regime in April, 2003.

A diplomat familiar with the IAEA, who spoke on condition of anonymity, discounted suggestions that the Americans might have carted off the equipment — most of it under IAEA seals — without informing the agency.

In Washington, State Department spokesman Richard Boucher said, "I think we share the general concern that some material might have gotten out into the market immediately after the war."

"But to the extent that all of us have been able to bring it under control, we have done that," he said.

The U.N. Monitoring, Verification and Inspection Commission known as UNMOVIC — which was responsible for overseeing the elimination of any banned Iraqi missile, chemical and biological weapons programs — said Iraqi authorities for over a year have been shipping thousands of tons of scrap metal out of the country.

The UNMOVIC report said those exports were handled by the Iraqi Ministry of Trade, which was under the direct supervision of U.S. occupation authorities until June 28, when the Americans handed power to Iraq's interim government. It said the shipments included at least 42 engines from banned missiles and other equipment that could be used to produce banned weapons.

UNMOVIC and IAEA inspectors left Iraq just before the U.S.-led invasion began in March 2003. The Bush administration then barred U.N. weapons inspectors from returning, deploying U.S. teams in an unsuccessful search for Iraqi weapons of mass destruction.

Nonetheless, IAEA teams were allowed into Iraq in June 2003 to investigate reports of widespread looting of storage rooms at the main nuclear complex at Tuwaitha, and in August to take inventory of "several tons" of natural uranium in storage near Tuwaitha.

ElBaradei said Iraq's interim Minister of Science and Technology Rashad Omar visited IAEA headquarters in Vienna in July, just after the handover of power from the U.S.-led coalition, to discuss the implementation of various Security Council resolutions.

A ministry delegation that visited in September asked the IAEA for assistance in selling the remaining nuclear material at Tuwaitha "with the exception of a small quantity to be retained for research purposes," in dismantling and decontaminating former nuclear facilities, and in resuming IAEA technical cooperation in a number of areas, he said.

"The agency is assessing the possibility of providing such assistance," ElBaradei said.

Iraq's Omar told the British Broadcasting Corp. that the missing equipment was taken by looters shortly after the invasion. The sites were then quickly secured by coalition forces and are now "well-protected" by the interim government "and there is no looting," he said.