The UN chief weapons inspector says there is no evidence that Iraq has weapons of mass destruction or is trying to build them.
But Hans Blix says there are still "many open questions" about Iraq's weapons programmes that need to be answered.
And he says that if Baghdad cooperates fully with inspections he could recommend he Security Council suspend sanctions within a year.
UN inspectors left Iraq ahead of US and British airstrikes in December 1998 to punish Saddam Hussein for not cooperating with inspections.
The Iraqi government had stopped cooperating after accusing part of the inspections team of feeding military intelligence back to the US in contravention of their remit.
Under council resolutions imposed after Iraq's 1990 invasion of Kuwait, sanctions cannot be lifted until inspectors certify that any weapons of mass destruction have been destroyed.
The US is trying to win international backing for attacking Iraq, claiming it is rebuilding its weapons programs. George W Bush is expected to make his case to the UN General Assembly on Thursday.
US deputy ambassador James Cunningham says the burden is on Iraq to prove that it does not have weapons of mass destruction. "The lack of evidence is not... evidence of absence," he said.
Blix says satellite photos show that Iraq has carried out rebuilding at sites that were bombed in 1998, "but this is not the same as saying there are weapons of mass destruction".