Tears welled in the US president's eyes as he gave his latest annual speech at Arlington National Cemetery in Washington, just a few days after admitting that he had some regrets about the Iraq conflict and that it had caused "consternation" in America.
"I'm in awe of the men and women who sacrifice for the freedom of the United States of America," Mr Bush said to loud applause from an audience that included Defence Secretary Donald Rumsfeld and US military chiefs.
"Our nation mourns the loss of our men and women in uniform. We will honour them by completing the mission for which they gave their lives, by defeating the terrorists, by advancing the cause of liberty and by laying the foundation of peace for a generation of young Americans," Mr Bush said.
The US death toll in Iraq is now about 2,470 and has increased by more than 800 since the president's last Memorial Day wreath-laying at Arlington Cemetery, in the Washington suburbs. Almost 300 US soldiers have died in Afghanistan.
There are the remains of about 296,000 US soldiers, mainly from the two World Wars and the Vietnam and Korean conflicts, at Arlington.
"In this place where valour sleeps, we are reminded why America has always gone to war reluctantly, because we know the costs of war," Mr Bush said.
"We have seen those costs in the war on terror we fight today. These grounds are the final resting place for more than 270 men and women who have given their lives in freedom's cause since the attacks of September 11, 2001."
The Iraq war is becoming increasingly unpopular and has become a major drag on the president's approval ratings which now hover around 30 percent. Polls indicate an overwhelming majority of Americans oppose the war.
Last week, after a summit with war ally Prime Minister Tony Blair of Britain, Mr Bush spoke of "setbacks and missteps" in the Iraq campaign.
He said that the Abu Ghraib prison scandal had been the biggest mistake in Iraq and that he regretted some of his rhetoric in the war on terror, such as his "Bring 'em on" taunt to Iraqi insurgents.
Mr Bush called it the "kind of tough talk that sent the wrong signal to people."