(CNN) -- Americans around the world paused Thursday to pay tribute to the country's military veterans and honor their ongoing sacrifices in Afghanistan, Iraq and elsewhere.
Vice President Joe Biden led remembrances at the Veterans Day National Ceremony in Virginia's Arlington National Cemetery, participating in a wreath-laying ceremony under clear blue skies at the Tomb of the Unknowns.
"I look out at all of you who have served our nation ... and I see the most tested among us, the most tested of all Americans," Biden said.
The more than 23 million surviving veterans today are "the heart and soul, the very spine of this nation," the vice president added.
Veterans Affairs Secretary Eric Shinseki, a retired U.S. Army general, called it a day for "promises that returning warriors will not bear their wounds alone."
They will be "embraced and cared for by a grateful nation," he declared.
President Barack Obama, participating in the G-20 economic summit in South Korea, marked the day with a visit to the U.S. Army garrison in Yongsan, near Seoul. In remarks to U.S. military personnel and their families, the president praised both American and South Korean troops who fought during the 1950-53 Korean War.
"Their service, through six decades, is a powerful reminder that security, democracy, and prosperity reinforce each other," he said.
Other civilian and military leaders also took part in ceremonies honoring veterans. Homeland Security Secretary Janet Napolitano was scheduled to assist in a wreath-laying and deliver remarks at the Coast Guard's World War I Memorial in Arlington. Countless mourners made their way past the Vietnam Memorial on the National Mall.
Parades and commemorations -- large and small, boisterous and quiet -- were held in cities and towns across the country. Birmingham, Alabama, was scheduled to hold its 63rd annual Veterans Day parade. Concerts were planned in Durham, North Carolina; Bath, New York; and Tucson, Arizona, according to the Department of Veterans Affairs.
New Haven, Connecticut, prepared to hold its third annual Veterans Run/Walk.
Twenty-five veterans were scheduled to take the oath of citizenship at Fort Sam Houston Cemetery in Texas, the VA noted.
Over three million disabled veterans played a prominent role in this year's remembrances. On Wednesday, ground was broken for a new monument in Washington -- the Americans Veterans Disabled for Life Memorial.
The memorial, to be located on 2.4 acres near the U.S. Capitol, will center around a star-shaped reflecting pool with an eternal flame.
Roberto "Bobby" Barrera, a severely injured Vietnam-era Marine who now heads the Disabled American Veterans, called the groundbreaking "a direct reflection of all disabled veterans and their journeys that began when they answered the call to duty."
"Those journeys continue throughout their honorable service, through the trauma of injuries, and it continues today through their recovery and their renewal of purpose."
Veterans Day originated as a commemoration of Armistice Day, which marked the conclusion of World War I. President Woodrow Wilson, America's commander-in-chief during the conflict, called it a day to "be filled with solemn pride in the heroism of those who died in the country's service."
CNN's Alan Silverleib, Lindy Royce and Paul Courson contributed to this report