United Nations weapons inspectors are preparing to return to Iraq to investigate the disappearance of equipment that could be used in atomic weapons.
The International Atomic Energy Agency said that equipment and materials that could be used to make atomic weapons had been disappearing from Iraq, but neither Baghdad nor Washington had noticed.
Following the revelations, the former UN chief weapons inspector, Hans Blix, has said the US had failed to control suspected nuclear sites in Iraq after last year's invasion, allowing crucial equipment to disappear.
Dr Blix said it was scandalous for the US to lose control of the situation after the end of the war.
Dr Blix's comments were echoed by the former senior American weapons inspector, David Kay.
He said it was inexcusable that the US had insufficient troops on the ground to prevent widespread looting after the first phase of military operations ended.
However, the US State Department spokesman, Richard Boucher, said the IAEA had two opportunities since to inspect facilities and make sure that materials were properly accounted for.
Mr Boucher said the US did not have detailed knowledge of what might have disappeared.
