The US Defence Secretary, Donald Rumsfeld, has said any country with an intelligence service knows that Iraq possesses weapons of mass destruction.
This follows Baghdad's repeated claim that it does not have any such weapons.
It is understood the Bush administration has asked the United Nations to step up the pace of arms inspections to increase the pressure on Iraq.
The UN Secretary General, Kofi Annan, has said he is pleased with the Iraqi government's co-operation with arms inspectors so far.
He was speaking after Iraq announced that it would be sending a declaration of its weapons programme to the UN on Saturday, one day ahead of schedule.
