Just hours after returning from his surprise trip to Afghanistan to honor troops overseas, President Obama today honored those who made the ultimate sacrifice.

Speaking at Arlington National Cemetery, following a wreath laying ceremony at the Tomb of the Unknown Soldier, Obama spoke of heroes "known and unknown" who are buried at "this holy space."

"The fallen patriots we memorialize today gave their last full measure of devotion. Not so we might mourn them, but we do. Not so that our nation might honor their sacrifice, although it does. They gave their lives so that we might live ours, so a daughter might grow up to pursue her dreams, so that a wife might be able to live a long life free and secure," he said.

"Everything that we hold precious in this country was made possible by those who gave their all. And because of them our nation is strong, safer and will always remain a shining beacon of freedom for the rest of the world," the president said.

Obama commemorated the 150th anniversary of the final resting place for more than 400,000 active duty service members, veterans and their families.

"On a spring day in 1864, Private William Christman of Pennsylvania was the first American to find eternal rest on these grounds," he said. "Over that century and a half, in times of war and times of peace Americans have come here; to pay tribute not only to not only the loved, ones that meant the world to them, but all our heroes - known and unknown."

The remembrance also leads into another war anniversary, Secretary of Defense Chuck Hagel noted.

"This Memorial Day has special meaning, given that next week marks the 70th anniversary of the D-day landing at Normandy, a day that was perhaps America's bloodiest day in all of World War II, a day with more than 10,000 allied casualties, such a staggering toll is difficult to comprehend."

U.S. President Barack Obama lays a wreath at the Tomb of the Unknown Soldier at Arlington National Cemetery, May 26, 2014, in Arlington, Virginia. (Drew Angerer/Getty Images)

Chairman of the Joint Chiefs of Staff General Martin Dempsey also spoke at today's ceremony, and Vice President Joe Biden in attendance with Dr. Jill Biden, and First Lady Michelle Obama sitting with fallen service members' children, who traveled to Washington to participate in the Tragedy Assistance Program for Survivors (TAPS) 20th annual Good Grief Camp.

President Obama paid tribute to the nearly 2,200 Americans killed during the war in Afghanistan and the ending of the war this year.

"For more than 12 years, men and woman like those I've met with [at Bagram Air Field] bore the burden of our nation's security. Now, because of their profound sacrifice, because of the progress they have made, we are at a pivotal moment," he said. "Our troops are coming home. By the end of this year, our war in Afghanistan will finally come to an end."

Remembering families of veterans, the president told stories of families who have lost loved ones, like 96-year-old Claire Edwards, who after 63 years, finally brought her husband Sergeant First Class Joseph Gantt home after his remains were identified last December. He also spoke to the young children of Staff Sergeant Michael Cardenaz, who died in Afghanistan four years ago

"We say to you and all these courageous children: your parents' bravery lives on in you. You will never walk alone. Your country will be there to help you grow up into the young men and woman your parents always knew you would be. And that's our pledge to you," Obama said.

The president also made another pledge to veterans, referencing the ongoing scandal surrounding the nation's medical care for military veterans and allegations of the secret waiting lists that hid long delays to see a doctors.

"We've been reminded in recent days, we must do more to keep faith with our veterans and their families, and make sure they get the care and benefits and opportunity that they've earned and they deserve," he said. "These Americans have done their duty. They ask nothing more than our country does our, now and for decades to come."

Just last week, deputy chief of staff for Obama, Rob Nabors, traveled to the Phoenix VA, where the scandal began.

The embattled VA Secretary Eric Shinseki was also in attendance at Arlington today.