Washington ? On the fourth anniversary of the Iraq war, President Bush and Congress’ Democratic leaders clashed over whether lawmakers should move to bring U.S. troops home – and whether they can.

With the House set to vote this week on a war spending bill that would effectively withdraw U.S. combat troops by next fall, Bush made clear he doesn’t think it’s lawmakers’ place to challenge his battle plan.

“They have a responsibility to ensure that this bill provides the funds and the flexibility that our troops need to accomplish their mission,” the president said in remarks televised from the White House. “They have a responsibility to pass a clean bill that does not use funding for our troops as leverage to get special interest spending for their districts. And they have a responsibility to get this bill to my desk without strings and without delay.”

Democrats countered that voters had put them in control of Congress to challenge Bush.

President Bush speaks Monday from the Roosevelt Room of the White House in Washington, D.C., as he marks the fourth anniversary of the war in Iraq.

“The American people have lost confidence in President Bush’s plan for a war without end in Iraq,” House Speaker Nancy Pelosi said.

With the war lumbering into its fifth year, it has claimed the lives of more than 3,200 members of the U.S. military. Predictions about the cost and length of the war have been far surpassed. Trying to halt spiraling sectarian bloodshed, Bush has ordered nearly 30,000 additional combat and support troops to Iraq, mostly to stabilize Baghdad.

The president pleaded for patience to give his strategy more time to work.

“The new strategy will need more time to take effect,” he said. “Until Baghdad’s citizens feel secure in their own homes and neighborhoods, it will be difficult for Iraqis to make further progress toward political reconciliation or economic rebuilding, steps necessary for Iraq to build a democratic society.”

From Capitol Hill, Democrats said patience has run out.

House Democratic Whip James Clyburn said Democrats were intent on “ending the blank check for the president’s war and setting a timeline for the phased redeployment of our U.S. military.”

Added Clyburn, D-S.C., “By August 2008 at the latest, U.S. combat troops will be redeployed from Iraq.”

A new poll reflected the stress and hopelessness that are the result of the unrelenting violence and uncertain political situation. The poll, by ABC News, USA Today, the BBC and ARD German TV, found only 18 percent of Iraqis have confidence in U.S. and coalition troops; 86 percent are concerned that someone in their household will be a victim of violence; and 51 percent say violence against American forces is acceptable.