Frank Buckles, in this file photo dated May 26, 2008, receives a US flag during Memorial Day activities at the National World War I Museum in Kansas City, Missouri. [Charlie Riedel / Associated Press]

MORGANTOWN, West Virginia - Frank Buckles, who lied about his age to get into uniform during World War I and lived to be the last surviving US veteran of that war, has died. He was 110.

Buckles, who also survived being a civilian POW in the Philippines in World War II, died peacefully of natural causes early on Sunday at his home in Charles Town, biographer and family spokesman David DeJonge said in a statement. Buckles turned 110 on Feb 1 and had been advocating a national memorial honoring veterans of World War I in Washington.

When asked in February 2008 how it felt to be the last of his kind, he said simply: "I realized that somebody had to be, and it was me." And he said he would have done it all over again, "without a doubt".

On Nov 11, 2008, the 90th anniversary of the end of the war, Buckles attended a ceremony at the grave of World War I General John Pershing in Arlington National Cemetery.

"I can see what they're honoring, the veterans of World War I," he told CNN.

He was back in Washington a year later to endorse a proposal to rededicate the existing World War I memorial on the National Mall as the official National World War I Memorial. He told a Senate panel it was "an excellent idea". The memorial was originally built to honor District of Columbia's war dead.

Born in Missouri in 1901 and raised in Oklahoma, Buckles visited a string of military recruiters after the United States entered the "war to end all wars" in April 1917. He was repeatedly rejected before convincing an Army captain he was 18. He was 16.

"A boy of (that age), he's not afraid of anything. He wants to get in there," Buckles said.

More than 4.7 million people joined the US military from 1917-1918.

The last known Canadian veteran of the war, John Babcock of Spokane, Washington, died in February 2010.

There are no French or German veterans of the war left alive.

Buckles served in the United Kingdom and France, working mainly as a driver and a warehouse clerk. The fact he did not see combat didn't diminish his service, he said: "Didn't I make every effort?"

An eager student of culture and language, he used his off-duty hours to learn German, visit cathedrals, museums and tombs, and bicycle in the French countryside.

After Armistice Day, Buckles helped return prisoners of war to Germany. He returned to the United States in January 1920.

Buckles returned to Oklahoma for a while, then moved to Canada, where he worked a series of jobs before heading for New York City. There, he again took advantage of free museums, worked out at the YMCA, and landed jobs in banking and advertising.

But it was the shipping industry that suited him best, and he worked around the world for the White Star Line Steamship Co and W.R. Grace & Co.

In 1941, while on business in the Philippines, Buckles was captured by the Japanese. He spent three years in prison camps.

"I was never actually looking for adventure," Buckles once said. "It just came to me."

He married in 1946 and moved to his farm in West Virginia in 1954, where he and wife Audrey raised their daughter, Susannah Flanagan. Audrey Buckles died in 1999.

Associated Press