The United States will have a formal response Thursday to Iraq's weapons declaration recently submitted to the United Nations.
Secretary of State Colin Powell and the U-S ambassador to the United Nations -- John Negroponte -- are expected to make an announcement on the Iraqi arms declaration after a presentation Thursday to the U-N Security Council by Chief U-N arms inspector Hans Blix.
The developments come as the United States and Britain are casting fresh doubts on the veracity of Iraq's claims that it possesses no weapons of mass destruction.
White House spokesman Ari Fleischer said Wednesday President Bush is concerned that Iraq has not disclosed all the details of its weapons program to United Nations inspectors. The president met with top aides Wednesday, amid reports he will declare Iraq in violation of the U-N resolution demanding that Baghdad disarm.
In Britain Wednesday, Foreign Secretary Jack Straw said Iraq's claim that it has no weapons of mass destruction is what he called "an obvious falsehood." British Prime Minister Tony Blair said his country will have a formal assessment of the Iraqi report after the Christmas holiday period.
Earlier, the top U-N nuclear inspector said there is no proof so far that Iraq has developed a nuclear program since the previous round of U-N inspections were held in 1998.
Mohamed Elbaradei -- in an interview published Wednesday in the Egyptian daily Al-Ahram -- says no evidence has surfaced that any Iraqi facilities have changed since the last inspections four years ago. But he added that the current round of inspections is still in a preliminary stage.
U-S officials have not revealed evidence that Iraq has nuclear weapons, but they say President Saddam Hussein is believed to have acquired equipment capable of developing such weapons.
The developments came as U-N weapons inspectors began their fourth week in Iraq -- visiting several sites in their search for weapons of mass destruction.
In an interview with Italian newspapers Wednesday, Iraq's Deputy Prime Minister Tariq Aziz said Iraq will fight "house-by-house" to defend Baghdad against any attack and will resist -- as he put it -- "to the last man."