BEIJING, China (CNN) -- Days after a Democratic congressman's call to withdraw U.S. troops from Iraq set off angry debate in Washington, President Bush said Sunday that leaving now would only embolden insurgents.Bush told reporters in China that Rep. John Murtha of Pennsylvania, a senior Democrat regarded as a defense hawk, was "a good man who served our country with honor and distinction as a Marine in Vietnam and as a United States congressman."But, Bush said, "I disagree with his position."The retired Marine colonel delivered an emotional statement Thursday, saying he had concluded that the presence of U.S. troops in Iraq was counterproductive because they had become a magnet for insurgent violence and that troops should be redeployed over six months. He also took a swipe at Vice President Dick Cheney and Bush, who have accused Democratic critics of playing politics during a war. "I like guys who've never been there who criticize us who've been there," Murtha said. (Watch Murtha's take on 'flawed policy wrapped in illusion' -- 8:11)Appearing Sunday on NBC's "Meet the Press," Murtha said, "I'm very hopeful that my proposal [of a four-step plan to get U.S. forces out of Iraq] is something they'll take seriously, that [Bush will] get a few of us to the White House and talk to us about this very difficult problem which the whole nation wants to solve with a bipartisan manner." Murtha said conditions in Iraq had changed since he wrote last year that an "untimely exit" could lead to civil war."It's different because there's no progress at all," Murtha said Sunday. The 17-term congressman said the U.S. needs to rethink its military strategy due to a persistent insurgency."... Since they're attacking our troops, and we have destabilized the area, I've changed my mind and I've come to the conclusion that now is the time to start to redeploy our troops to the periphery and let the Iraqis take over," Murtha said. A decidedly different toneIn his remarks Sunday, the president used a decidedly different tone than was heard from the administration on the day of Murtha's comments, when White House spokesman Scott McClellan compared the congressman to anti-war filmmaker Michael Moore.McClellan said it is "baffling that [Murtha] is endorsing the policy positions of Michael Moore and the extreme liberal wing of the Democratic party."McClellan called Murtha, who earned a Bronze Star and two Purple Hearts for his service in Vietnam, "a respected veteran and politician who has a record of supporting America." (Watch Democrats defend Murtha's character -- 3:13)But, McClellan added, "The eve of an historic democratic election in Iraq is not the time to surrender to the terrorists." Bush, in China as part of an eight-day tour of Asia, said Murtha was a strong supporter of the military who had come to his decision "in a careful and thoughtful way."But Bush reiterated his policy that U.S. troops will stay in Iraq until that country's security forces can stand on their own. "An immediate withdrawal of our troops from Iraq will only strengthen the terrorists' hand in Iraq and in the broader war on terror," Bush said. The president said the Sunni-dominated insurgency's goal was to "break our will" so that an early withdrawal would lead to "a safe haven for terror."Leaving Iraq prematurely, he said, is "not going to happen, so long as I'm the president."After Murtha's statement, House GOP leaders tried Friday to force Democrats to take a stand on a quick exit from Iraq by bringing up a resolution calling for the immediate withdrawal of U.S. troops. The resolution was soundly defeated, with only three yes votes. (Full story)Democrats called the resolution a political stunt.Nearly 2,100 American troops have died in Iraq since the March 2003 invasion that toppled Iraqi dictator Saddam Hussein -- a war that top U.S. officials said was needed to strip Iraq of illicit stockpiles of chemical and biological weapons and efforts to produce a nuclear bomb. No such stockpiles have been found since Hussein's government collapsed in April 2003. CNN's Dana Bash contributed to this report.