Speaking at George Washington University in the capital today, Bush also accused Iran of contributing to the unrest in Iraq, saying Tehran is helping build lethal improvised explosive devices.
On the ground, bomb blasts went off in several Iraqi towns, killing at least four people, including a U.S. soldier. In Baghdad, police found the bodies of four executed men.
Meanwhile Britain said it will reduce its presence in Iraq by 800 troops, or 10 percent of its contingent, by May.
Hussein Trial Adjourned
Also today, the trial of former Iraqi president Saddam Hussein and seven of his former colleagues was adjourned until March 15.
In today's session, a former judge under Hussein's regime, Awad Hamed al-Bandar, defended the legality of the death warrants he issued for dozens of men accused of trying to assassinate the former leader in the 1980s.
The defendants have been on trial since October over the killing of the 148 men from the mainly Shi'ite town of Al-Dujayl after an assassination attempt on Hussein in 1982.
(compiled from agency reports)