The United States has responded to requests from the International Atomic Energy Agency to allow inspectors back in Iraq.

The IAEA says it has a verbal offer from the U.S. mission in Vienna to allow inspectors to return to Iraq and safeguard nuclear material. The response came after IAEA chief Mohamed ElBaradei said he feared a radiological emergency was developing that could get out of control. Mr. ElBaradei is disturbed by media reports of looting and destruction at important nuclear sites. Mark Gwozdecky, a spokesman for the agency, said the U.S. response came early Wednesday.

"We were officially informed this morning, and we're currently in discussions with the U.S. government regarding modalities, or arrangements, for an IAEA mission to go to the Iraqi nuclear research center at Tuwaitha," he said. "We have precise inventories of nuclear material stored there prior to the hostilities, so we're in a good position to determine what has gone missing and what needs to be done to re-establish control over that material."

Mr. Gwozdecky says discussions concern transport and accommodation arrangements as well as who does what.

He stressed that, "time is of the essence if material has, indeed, been stolen." There is the danger that terrorists could build a so-called dirty nuclear bomb, besides the possibility of widespread contamination.

The United States has so far mentioned only the Tuwaitha nuclear plant, just south of Baghdad, for possible United Nations inspection.

Mr. Gwozdecky says the IAEA knows the site well. The agency's inspectors have monitored radioactive material there over the last 12 years.