President Obama paid tribute at a Veterans Day ceremony at Arlington Memorial Cemetery to "the heroes over the generations who have served this country of ours with distinction."
He said the wreath he laid earlier at Tomb of the Unknowns was intended to "remember every service member who has ever worn our nation's uniform."
In a speech at the Memorial Amphitheater, he said America will never forget the sacrifice made by its veterans and their families.
"No ceremony or parade, no hug or handshake is enough to truly honor that service," the president said, adding that the country must commit every day "to serving you as well as you've served us."
He spoke of the Sept. 11 generation, "who stepped forward when the Towers fell, and in the years since have stepped into history, writing one of the greatest chapters in military service our country has ever known. You've toppled a dictator and battled an insurgency in Iraq. You pushed back the Taliban and decimated al-Qaida in Afghanistan. You delivered justice to Osama bin-Laden."
Obama also said this was the first Veterans Day in a decade with no American troops fighting and dying in Iraq, and that a decade of war in Afghanistan is coming to a close.
Over the next few years, he said, more than 1 million service members will make the transition to civilian life. "As they come home, it falls to us, their fellow citizens, to be there for them and their families, not just now but always."
Later, the president and his wife, first lady Michelle Obama, and Vice President Biden and his wife, Jill, greeted families in the cemetery's Section 60, home to graves of service members killed in Afghanistan and Iraq