The United States marked on Monday the annual Memorial Day as politicians and public paid tribute to the country's troops who died in battles.

President George W. Bush appeared at a national cemetery in Arlington, Virginia accompanied by his wife, Laura, and Defense Secretary Robert Gates, saying national leaders must have "the courage and character to follow their lead" in preserving peace and freedom.

US President George W. Bush speaks during Memorial Day ceremonies at Arlington National Cemetery in Arlington, Virginia, May 26, 2008. (Xinhua/Reuters Photo) 

"On this Memorial Day, I stand before you as the commander in chief and try to tell you how proud I am," he told an audience of thousands of people, including military figures, veterans and their families.

Prior to the speech, he placed a wreath at the Tomb of the Unknowns that contains the remains of unidentified US soldiers from World Wars I and II, and the Korean War.