President Barack Obama has paid tribute to US forces at a ceremony at the military cemetery in Arlington, Virginia, on Memorial Day.He addressed an audience of serving soldiers, veterans and families of those killed in combat.
Mr Obama said: "The grief of mourning you carry in your hearts is a grief I cannot fully know.
"This day is about you and the fallen heroes that you loved and it's a day that has meaning for all Americans."
Earlier, he met relatives of soldiers who died and he laid a wreath at the Tomb of the Unknown Soldier.
President Barack ObamaOur nation owes a debt to its fallen heroes that we cannot ever fully repay”
His speech took place in the Arlington amphitheatre in front of a flag-draped wall.He said: "To those of you mourn the loss of a loved one today, my heart goes out to you."
He added: "We remember that the blessings that we enjoy as Americans came at a dear cost.
"Our nation owes a debt to its fallen heroes that we cannot ever fully repay. But we can honour their sacrifice, and we must."
Defence Secretary Robert Gates also paid tribute to the armed forces.
On Sunday, an annual motorbike rally and a concert in Washington DC were also part of the memorial celebrations.
Sarah Palin was among those who attended the rally, Rolling Thunder, although she did not address the crowds.