UPDATED 3:11 p.m. ET
(CBS News) President Obama on Monday paid tribute to missing and fallen U.S. forces, laying a wreath at the Tomb of the Unknown Soldier and marking the 50th anniversary of the Vietnam war at the Vietnam Veterans Memorial.
"They rest here, together, side by side, row by row, because each of them love this country, and everything it stands for, more than life itself," Mr. Obama said in his remarks at Arlington National Cemetery.
"Today we come together as Americans to pray, to reflect and to remember these heroes, but tomorrow this hallowed place will once again belong to a smaller group of visitors who make their way through the gates and across these fields, in the heat and in the cold, in the rain and the snow, following a well-worn path to a certain spot and kneeling in front of a familiar headstone. You are the family and friends of the fallen," Mr. Obama said.
Originally known as Decoration Day, Memorial Day is an annual celebration often celebrated with backyard barbecues that is intended to give Americans a chance to remember the sacrifices made by those who have served in the American military.
The Vietnam Memorial event was billed as the start of a 13-year program to mark the 50th anniversary of the war in which 58,000 soldiers, sailors and airmen died before the war's end in 1975.
"You looked after one another. You cared for one another," Mr Obama told the assembled crowed, which included Vietnam veterans.
"Just as importantly, you didn't just take care of your own. You cared for those that followed. You made it your mission to make sure today's troops get the respect and support that all too often you did not receive," he added.
"Because of you, across America, communities have welcomed home our forces from Iraq. And when our troops return from Afghanistan, America will give this entire 911 generation the welcome home they deserve," he told the Vietnam veterans.
Mr. Obama's Republican rival for the White House, Mitt Romney,, a decorated war hero who lost to Mr. Obama four years ago.
The race between Mr. Obama and Romney marks the first time in modern presidential politics that neither of the two main candidates for president have served in the military.
Mr. Obama noted that the war in Iraq is over and the war in Afghanistan is "winding down."
"This Memorial Day, we mark another milestone. For the first time in nine years, Americans are not fighting and dying in Iraq. We are winding down the war in Afghanistan, and our troops will continue to come home. After a decade under the dark cloud of war, we can see the light of a new day on the horizon," Mr. Obama said at Arlington.