President Bush is continuing his battle with opposition Democrats calling for the withdrawal of troops from Iraq. Mr. Bush spoke to American troops at a U.S. air base in South Korea following the close of a regional economic summit.

President Bush came to Osan Air Base to thank U.S. troops for helping to keep the peace on the Korean peninsula for the more than 50 years since the end of fighting in the Korean War.

But it is today's war in Iraq that drew the most attention in the president's speech as he again answered opposition Democrats calling for U.S. troops there to come home.

"In Washington there are some who say that the sacrifice is too great, and they urge us to set a date for withdrawal before we have completed our mission," the president said. "Those who are in the field know better. One of our top commanders in Iraq, Major General William Webster, says that setting a deadline for our withdrawal from Iraq would be, quote a recipe for disaster. General Webster is right."

President Bush told a crowd of troops wearing camouflage uniforms in an airplane hangar that their work for peace and freedom involves great sacrifice. He says their colleagues in Iraq are hunting down terrorists and helping the Iraqi people build a working democracy in the heart of the Middle East. It is a mission that the president says would be compromised by bringing troops home too soon.

"So long as I am Commander-in-Chief, our strategy in Iraq will be driven by the sober judgment of our military commanders on the ground," he said. "We will fight the terrorists in Iraq. We will stay in the fight until we have achieved the victory our brave troops have fought for."

More than 2,000 Americans have been killed in Iraq since the U.S.-led invasion to topple Saddam Hussein.

The mounting death toll and continuing insurgency have increased calls by some Democrats to get U.S. troops out of Iraq.

A senior Democratic leader on defense issues joined that call this past week, saying the military has accomplished its mission in Iraq and its duty is done. Congressman John Murtha said U.S. troops have become a catalyst for violence as the primary targets of insurgents in Iraq. The war is not going as advertised, he said, calling it a flawed policy wrapped in illusion.

President Bush did not mention Congressman Murtha by name during his remarks here in South Korea, but White House officials have launched a blistering rebuke of the Vietnam War veteran.

White House Press Secretary Scott McClellan said it is baffling that the Pennsylvania lawmaker is now endorsing the policies of the extreme liberal wing of the Democratic Party, saying a troop withdrawal would be surrendering to terrorists on the eve of historic democratic elections next month in Iraq.