U.N. experts in New York and Vienna studied Iraq's voluminous weapons dossier on Monday to establish whether it has been a full disclosure and to see how close Baghdad came to making an atomic bomb. The results of their work, which was expected to keep the dossier under wraps for at least a week, will be keenly awaited by the United States, which Iraq has challenged to produce evidence to justify its threats of war.

Washington stressed on Monday it would wait and see what was in the 12,000-page document flown from Baghdad on Sunday. But it made clear it was ready to take military action if necessary to rid Iraq of doomsday weapons it believes President Saddam Hussein possesses.

U.S. Deputy Secretary of State Richard Armitage said on a visit to Tokyo that President Bush "has patience."

"He would much prefer to have Iraq disarm herself," Armitage told reporters. "But, as the president said, 'If Iraq won't disarm, then eventually, Iraq will be disarmed."'

Armitage's words underlined Bush's message that U.S. forces were ready to strike if the weapons inspection process launched by a November 8 U.N. resolution fails to satisfy U.S. objectives to disarm Saddam.

ATOMIC BOMB?

Although Iraq insists it has no nuclear, biological or chemical weapons, a top Saddam aide hinted on Sunday it may have been near to making an atomic bomb. He invited the International Atomic Energy Agency (IAEA) to see how close Baghdad came.

"We have the complete documentation from design to all the other things. We haven't reached the final assembly of a bomb nor tested it," Amir al-Saadi told journalists.

"It is for the IAEA to judge how close we were," he said, adding: "If I tell you we were close, it is subjective."

It was not clear why they returned again to the country's main nuclear program facility, which is the location of the Osirak reactor bombed by Israel in 1981. Several tons of uranium have been under seal by the IAEA at Tuweitha since 1998.

In an indication of how long the latest round of inspections could take, IAEA Director General Mohamed ElBaradei said he believed patience would be needed.

Asked in Tokyo about reports the inspection process could take up to a year, he said: "I think that's accurate."

The U.N. ordered Iraq to destroy its weapons of mass destruction after Baghdad's 1990 invasion of oil-rich neighbor Kuwait.

Iraqi troops were ousted in the 1991 Gulf War.

Experts at the U.N.'s IAEA nuclear watchdog received the section of Iraq's report relevant to them, estimated at about 2,000 pages, at their Vienna headquarters on Sunday.

The entire Iraqi dossier consists of 11,807 pages, 352 pages of supplements and computer disks with 529 megabytes of data.

It was handed over on the day of a deadline set by last month's U.N. resolution 1441 for Iraq to give a full account of any past and current weapons of mass destruction programs.

The dossier is also being studied in New York at the headquarters of the U.N. arms inspection agency UNMOVIC, which handles the part dealing with biological and chemical activities. Chief U.N. arms inspector Hans Blix said his team would set to work at once.

Diplomats said the dossier was not expected to be released for about a week, since it must be purged of information other nations or terrorists might use to build weapons.

First word on the documents' content is likely to surface on Tuesday when Blix attends the monthly lunch of the 15 Security Council ambassadors and U.N. Secretary-General Kofi Annan.

One council diplomat said he expected 90 percent of the documents to contain information submitted in past Iraqi declarations. "It's the other 10 percent we are interested in," he said.

IRAQI CHALLENGE TO U.S.

Even before the documents were delivered or seen, the White House insisted it had evidence, not given to U.N. weapons inspectors, that Iraq had retained or even accelerated arms programs in the four years since inspectors last conducted searches.

Iraq's Saadi challenged the United States to provide the U.N. inspectors with evidence of doomsday weapons, insisting Iraq had none.

"If they have anything to the contrary, let them come up with it, give it to the IAEA, give it to UNMOVIC. They are here, they could check it. Why play this game?" he told journalists, adding the declaration was "accurate...comprehensive, truthful."

Hussam Mohammed Amin, head of Iraq's National Monitoring Directorate, has said the declaration detailed "some activities that are dual-use," referring to technology that has both peaceful and military applications.

U.S. officials said on Friday Washington was expected to declare Iraq in "material breach" of U.N. resolution 1441 if it stated it had no banned weapons.

But they said Washington would not cite the breach as immediate grounds for war, letting U.N. inspections continue while Bush courted partners to help strike Iraq if needed.

U.N. arms inspectors must report to the Security Council by January 26 under U.N. resolution 1441, which threatens Iraq with "serious consequences" if it fails to comply. They can flag any Iraqi violations sooner

PHOTO CAPTION

Documents are carried into the United Nations by Surya Sinha, a UN weapons inspector (L) after making their way from Iraq to New York on December 8, 2002. Chief United Nations Weapons inspector Hans Blix (R) greeted the UN arms inspectors as they arrived into the building. (Chip East/Reuters)