VIENNA, Oct 13: United Nations inspectors, barred from most of Iraq since last year's invasion, are ready to return to probe the disappearance of equipment that could be used in atomic weapons, the United Nations nuclear watchdog said on Wednesday.

"We are ready, subject to Security Council guidance and the prevailing security situation, to resume our Security Council mandated verification activities in Iraq," International Atomic Energy Agency (IAEA) spokesman Mark Gwozdecky said.

The IAEA, which monitored Saddam Hussein's nuclear sites before last year's Iraq war, informed the UN Security Council this week that equipment and materials that could be used to make atomic weapons have been vanishing from Iraq but neither Baghdad nor Washington had noticed.

"This is another screw-up by the US," David Albright, a former UN weapons inspector and president of the Institute for Science and International Security think-tank, said. "They should have let the IAEA inspectors go in long ago."

Former chief UN weapons inspector Hans Blix, whom Washington had harshly criticised before the Iraq invasion for suggesting Saddam might not have any banned weapons programmes, said the entire Iraq project had ended in "tragedy and failure".

Iraq's Science and Technology Minister Rashad Omar said everything at the nuclear sites belonging to his ministry was accounted for and that there had been no recent disappearances.

He said nothing had gone missing since a looting spree after the US-led invasion in March 2003. But a Western diplomat close to the IAEA said Omar's comments did not appear to apply to the sites the IAEA was really worried about - which may belong to Iraq's defence ministry.

Omar specifically referred to the Iraqi nuclear research complex at Tuwaitha near Baghdad, the one site where the IAEA has conducted limited inspections last year and this year.

"The concerns raised in the (IAEA) letter centre around material and equipment in dozens of other facilities, most of which are part of the broader complex of former military-related facilities," the diplomat said. -Reuters