The nearly 2 tons of low-enriched uranium and approximately 1,000 highly radioactive items could be used in so-called "dirty bombs." The material had been placed under seal by the International Atomic Energy Agency at the Tuwaitha nuclear complex, 12 miles south of Baghdad, U.N. officials said Wednesday.
The United States disclosed Tuesday that the material was secured from Iraq's former nuclear research facility and airlifted out of the country to an undisclosed Energy Department laboratory for further analysis last month.
"The American authorities just informed us of their intention to remove the materials, but they never sought authorization from us," said Gustavo Zlauvinen, head of the IAEA's New York office.
Under U.N. resolutions adopted after the 1991 Gulf War, the IAEA was authorized to oversee the destruction of Iraq's nuclear program and monitor its activities to ensure that the program was not revived.
Paul Longsworth, deputy administrator for defense nuclear nonproliferation in the U.S. National Nuclear Security Administration, said Wednesday the United States didn't need IAEA approval for the transfer.
"We believe we have the legal authority to do it," he said. "We are in custody of the material only, and we have the permission of the Iraqi government to take this out of the country."
Energy Secretary Spencer Abraham, in disclosing the secret airlift Tuesday, called it "a major achievement" in efforts to "keep potentially dangerous nuclear material out of the hands of terrorists."
The airlift ended on June 23, five days before the United States transferred sovereignty to Iraq's new interim government.
IAEA Director General Mohamed ElBaradei said in a letter to the Security Council circulated Wednesday that Washington informed the agency on June 19, 2003, that "due to security concerns" it intended to transfer some nuclear material stored at Tuwaitha to the United States.
At the time, the agency took note of the U.S. intention to remove the nuclear material "from agency verification … and only expressed a view on the agency's verification requirements," he said.
A U.N. official, speaking on condition of anonymity, said there was some concern about the legality of the U.S. transfer because the nuclear material belonged to Iraq and was under the control and supervision of the IAEA.
Longsworth said the material was now at a facility where it can be examined by the IAEA.
In 1992, after the first Gulf War, all highly enriched uranium — which could be used to make nuclear weapons — was shipped from Iraq to Russia, the IAEA's Zlauvinen said.
After 1992, roughly 2 tons of natural uranium, or yellow cake, some low enriched uranium and some depleted uranium was left at Tuwaitha under IAEA seal and control, he said.
So were radioactive items used for medical, agricultural and industrial purposes, which Iraq was allowed to keep under a 1991 U.N. Security Council resolution, Zlauvinen said.
IAEA inspectors left Iraq just before last year's U.S.-led war. After it ended, Washington barred U.N. weapons inspectors from returning, deploying U.S. teams instead in a search for Iraqi weapons of mass destruction. That search has been unsuccessful so far.
An exception was made in June 2003 when Washington allowed an IAEA team to go to Tuwaitha to secure uranium afterwhen the fighting ended.
The IAEA recovered most missing material and Zlauvinen said the uranium was put in sealed containers and left for the Americans to guard.
But because U.S. authorities restricted inspections of Tuwaitha, the IAEA team was unable to determine whether hundreds of radioactive items used in research and medicine across the country were secure.
In other developments related to the hunt for weapons of mass destruction:
But The New York Times reports the Senate intelligence committee's findings will not include any review of the way Bush administration officials used the intelligence data in making the case for war.
Critics have said the president and others exaggerated what spy agencies had observed.
A subsequent report — likely to come out after the presidential election — will address the way the case for war was made.
Blair said Tuesday that Saddam Hussein's illicit weapons of mass destruction may never be found in Iraq, but insisted the dictator had posed a threat to the world.
"We do not know what has happened to them. They could have been removed, they could have been hidden, they could have been destroyed," Blair said.
"To go to the opposite extreme and say therefore no threat existed from Saddam Hussein would be a mistake," he told the House of Commons Liaison Committee.