Washington, Nov 30. (AP): President George W. Bush said Tuesday that ``it would be a terrible mistake'' to pull U.S. forces out of Iraq and that politics should not play any part in a decision about withdrawal.

``We will make decisions about troops levels based upon the capability of the Iraqis to take the fight to the enemy,'' Bush said. ``I will make decisions on the level of troops based upon the recommendations of commanders on the ground.''

The argument against withdrawal was echoed in Washington by Defense Secretary Donald H. Rumsfeld, who said quitting the war would allow insurgents to prevail and put the United States ``at still greater risk.''

``Quitting is not an exit strategy,'' Rumsfeld said at a news conference.

On the other hand, Rumsfeld made clear that the time has arrived to wean the Iraqis of their dependence on American support for security _ whether it's guarding Iraq's borders or protecting its power plants.

``They have to do it for themselves,'' Rumsfeld said. ``There isn't an Iraqi that comes into this country and visits with me that doesn't say that. They know that. They know that they're the ones that are going to have to grab that country. And it's time.''

Bush and Rumsfeld spoke in advance of a speech by the president on Wednesday at the U.S. Naval Academy. The remarks are expected to outline the administration's strategy for giving Iraqi forces increasing responsibility for the security of their country.

The war in Iraq and the mounting number of American casualties have contributed to a steep drop in Bush's popularity. His approval rating is at the lowest level of his presidency.