WAR ON TERROR

Bush argued that fighting Islamic militants in Iraq helped to prevent attacks on targets in the US.

"The terrorists who murder the innocent in the streets of Baghdad want to murder the innocent in the streets of American cities," he said.

"Defeating this enemy in Iraq will make it less likely we will face this enemy here at home."

Democratic Party presidential candidate Barack Obama said the decision to invade was made on ideological grounds, instead of "reason and facts".

Bush spoke as anti-war protests were held in several US cities amid mounting opposition to the war and its costs.

In his speech, Mr Bush dismissed what he called "exaggerated estimates" of the war's price tag.

"The costs are necessary when we consider the cost of a strategic victory for our enemies in Iraq," he said.

He said recent troop reinforcements had brought about "a major strategic victory in the broader war on terror".

He also made the case that by working with Sunni Arabs from so-called Awakening Councils to defeat al-Qaeda, the US was successfully driving a wedge between militants and the Arab mainstream.

"In Iraq," he said, "we are witnessing the first large-scale Arab uprising against Osama Bin Laden. And the significance of this development cannot be overstated."