A senior Iraqi official on Wednesday played down concerns about the reported disappearance from Iraq's nuclear facilities of high-precision equipment that could be used to make weapons, saying all sites under the interim government's control have been secured.

Iraq's interim science and technology minister, Rashad Omar, invited the International Atomic Energy Agency (search) to visit the sites at any time and promised full cooperation with the U.N. watchdog.

In a letter to the U.N. Security Council (search) on Monday, IAEA director-general Mohamed ElBaradei (search) said satellite photos and follow-up investigations show "widespread and apparently systematic dismantlement" at sites related to Iraq's nuclear program that had once been subject to stringent monitoring.

Omar said the missing equipment — which the IAEA says includes milling machines and electron beam welders — was taken in the looting spree that broke out immediately after last year's invasion, which the United States said aimed to rid Iraq of its weapons of mass destruction. The sites were quickly secured by coalition forces before they were turned over to Iraqi authorities with the formal handover of sovereignty in June, he said.

"The locations under my control are very well protected," Omar said in an interview with The Associated Press. "Not even a single screw is being taken away without my knowledge."

He said if anything did go missing, Iraq would inform the IAEA itself.

While some industrial material that Iraq sent overseas has been located in other countries, ElBaradei said no high-precision items, which can be used both commercially and in nuclear weapons production have been found.

Since the equipment's disappearance could be "of proliferation significance," he said "any state that has information about the location of such items should provide IAEA with that information."

The United States said Tuesday it will conduct "a full investigation" along with the Iraqi government into the reported disappearances.

IAEA inspectors left Iraq just before the war began in March 2003. President Bush's 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 satellite photos showed entire buildings that had held precision equipment were being dismantled at some sites.

Omar refuted the report, saying eight buildings at Tuwaitha were being renovated to turn the site into a "peaceful, scientific research park." Hundreds of security guards trained by U.S. forces were protecting the facility, he said.

"We are transparent," he said. "The IAEA can come at any time to look at the facilities."