First World War veteran Henry Allingham bows after his wreath was laid at the steps of the Cenotaph in London on Tuesday. (Alastair Grant/Associated Press)

Veterans, world leaders and everyday citizens attended ceremonies around the world Tuesday to mark the 90th anniversary of the end of the First World War, which devastated Europe and claimed millions of lives.

In the United Kingdom, three of the four remaining British survivors honoured 700,000 of their comrades who gave their lives.

Henry Allingham, 112, Harry Patch, 110, and Bill Stone, 108, led the country in observing two minutes of silence at 11 a.m. local time in London at the Cenotaph, a British war memorial.

Allingham was in the Royal Air Force, Patch served in the army and Stone was a member of the Royal Navy.

"I'm glad to be here. It means a lot to me," BBC News quoted Allingham, Britain's oldest man, as saying. "I hope people realize what my pals sacrificed on their behalf."

Representatives from the armed forces laid down wreaths on behalf of the men, who sat in silence in their wheelchairs, in the presence of British Prime Minister Gordon Brown and Defence Secretary John Hutton.

The surviving veterans of the war have dwindled to a frail few. France, Germany and Turkey this year lost their lone survivors.

World leaders gather for ceremony in France

French President Nicolas Sarkozy and Britain's Prince Charles attended a solemn ceremony Tuesday morning in Douaumont, France, near one of the conflict's bloodiest battlefields.

From left: Australian Gov. Gen. Quentin Bryce, German Bundesrat President Peter Mueller, French President Nicolas Sarkozy, French Prime Minister Francois Fillon, Britain's Prince Charles and Luxemburg Grand Duc Henri stand during a ceremony commemorating the end of the First World War in Douaumont, eastern France, on Tuesday. (Remy de la Mauviniere/Associated Press)

Douaumont is in France's northeast, near the site of the Battle of Verdun, where an estimated 300,000 soldiers lost their lives in 300 days of fighting between French and German troops for control of River Meuse, a key strategic post on the eastern approach route from Germany to Paris. The French forces prevailed in December 1916.

Sarkozy stressed how far Europe had come since the end of the conflict often referred to as the Great War.

"It is upon the blood shed by the soldiers of the Great War ... that was built the great dream of human brotherhood, the great dream of peace, of comprehension, of respect, the great dream which has a name: Europe," he said.

Special ceremony planned for Ypres

Prince Charles, Quentin Bryce, Australia's governor general, Sarkozy and Peter Mueller, president of the upper house of the German parliament known as the Bundesrat, laid wreaths at the foot of a massive French flag that soared over the esplanade between two large fields of burial markers.

Hundreds of people including veterans from other wars stood outside a huge stone ossuary in Douaumont, where unknown soldiers from both sides of the war are buried.

Canadian World War II veterans attend official ceremonies to mark the 90th anniversary of the end of the First World War in Mons, Belgium, on Tuesday. (Michel Spingler/Associated Press)

A commemoration ceremony also took place in Mons, Belgium, where the last commonwealth soldier — a Canadian — died in the war.

"Wreaths were laid [and] there was a parade through the streets of the city," said the CBC's Tom Parry, reporting from Mons.

"Later on this evening there will be a special ceremony in Ypres for … the 68,000 Canadians who died during the First World War," said Parry.

Ypres is a Belgian town that was the site of many battles and the inspiration for the poem In Flanders Fields, penned by Canadian soldier Lt.-Col. John McCrae on May 3, 1915.

During the 1914-1918 war, more than 600,000 Canadian soldiers volunteered to go overseas. More than 66,000 Canadian soldiers were killed and 172,000 wounded.

Bush praises veterans

U.S. President George W. Bush, making an appearance at a Manhattan pier that houses the Second World War aircraft carrier U.S.S. Intrepid, marked the day by praising past and present veterans.

"Veterans have inspired me," Bush said in a speech before attending a rededication ceremony of the Intrepid Air, Sea and Space Museum. "I was raised by a veteran. I appreciate the commitment to our country that the veterans have made."

The U.S.S. Intrepid was decommissioned in 1974.

Earlier, thousands of Australians paused Tuesday to remember those who died in a war that a government minister said had decimated a generation.

Drawn from a population of fewer than five million people, 60,000 Australian soldiers died in combat.

As part of ceremonies across Australia, a minute of silence was observed as the 11th hour struck across five different time zones spanning two hours.

With files from the Associated Press