President Bush has called on Americans to rededicate themselves to the cause of freedom, as the nation remembers its war dead on this Memorial Day weekend. Marissa Melton reports from Washington.

In his weekly radio address, President Bush urged Americans to honor those who have given their lives in service to the nation as well as those who are defending freedom around the world today. He told the story of Sergeant David Christoff of Ohio, a U.S. Marine who enlisted immediately following the September 11, 2001 attacks on the United States.

"Asked why he made the decision to serve, David said: 'I don't want my brother and sister to live in fear,'" he said.

Mr. Bush said Christoff earned a medal for wounds suffered in street battles in the Iraqi city of Fallujah, and later requested a second tour in Iraq because he believed there was a job to finish there. Christoff died in Anbar province a year ago. But Mr. Bush said, even in death, Christoff found a way to express his concern and support for his fellow soldiers.

"When his family received his belongings, his mother and his father each found a letter from David. He asked that they pray for his fellow Marines and all those still serving overseas," he said.

A flag placed by a Boy Scout sits in front of a World War II soldier's head stone at Long Island National Cemetery in Farmingdale, New York, 26 May 2007

In the Democrats' radio address, former Marine Elliott Anderson, a veteran of the war in Afghanistan, said he was proud to serve his country but that he and some of his fellow service members oppose U.S. involvement in Iraq.

"I know I speak for many of my friends overseas when I say that the best way to honor the troops is to responsibly end our involvement in Iraq's civil war," he said.

President Bush is spending Memorial Day weekend at Camp David, the presidential mountain retreat near Washington. Before he left Friday, he presented five Purple Heart medals to wounded service members at the National Naval Medical Center. Monday, he returns to the nation's capital to lay a wreath at the Tomb of the Unknown Soldier in Arlington National Cemetery.