OTTAWA -- A crowd of hundreds gathered under a clear sky in the biting cold in Ottawa this morning for a Remembrance Day service at the National War Memorial.

Gov. Gen. Julie Payette, in her first Remembrance Day since becoming commander-in-chief of Canada's armed forces, laid the first wreath at the event.

Canadians are pausing across the country -- and around the world -- to reflect on the sacrifices made in past and present conflicts.

Prime Minister Justin Trudeau did not attend this year's national service, instead taking part in a ceremony of remembrance in Vietnam, where he's attending the APEC leaders summit.

He marked the day by reciting a poem and singing the national anthem alongside Canadian military personnel.

Later, Payette will host a luncheon in honour of this year's national Silver Cross Mother, Diana Abel, who lost her son, Cpl. Michael David Abel, while serving in Somalia in 1993.

Special attention is also being paid this year to several key battles from the First and Second World Wars, including the 100th anniversary of the Battle of Passchendaele, which ended on Nov. 10, 1917.

More than 4,000 Canadians were killed and 12,000 were wounded in Passchendaele, which Prime Minister Justin Trudeau described as a symbol of the worst horrors of the First World War.

"Our soldiers fought an impossible fight with perseverance, valour, and commitment to a greater cause," Trudeau said in a statement issued Friday.

"Nine Canadians would earn the Victoria Cross for their bravery. Yet the battle came at a devastating cost."

In Danang on Saturday, Trudeau joined nearly 100 people in a hotel conference room for a ceremony that began about an hour after his closing news conference at the APEC summit.

He recited the French poem, "Le dormeur du val," and Foreign Affairs Minister Chrystia Freeland read "In Flanders Fields." A bugler then played "Last Post" and the room sang the national anthem.

This year also marked a century since the April 1917 Battle of Vimy Ridge, which saw nearly 3,600 Canadians killed and more than 7,000 wounded, and 75 years since the Dieppe Raid of the Second World War.

Icy temperatures also prevailed in Toronto where hundreds of people gathered to pay their respects in the downtown core.

Mayor John Tory said the wintry conditions seemed appropriate given the purpose of the gathering.

"That is, I think, a good thing within the context of Remembrance Day," Tory said of the weather. "Because it might just give us the tiniest sense of the devastating circumstances in which our service men and women did their duty on our behalf in many past conflicts."

Tory particularly highlighted the battle of Passchendaele, which concluded 100 years ago Friday.

In Halifax, hundreds of people packed the Grand Parade, and doves flew overhead as rows of uniformed men and women removed their hats to pay their respects to fallen soldiers.

Several Howitzer cannons will send thunderous echoes across the capital today as members of the 30th Field Artillery Regiment, Royal Canadian Artillery, fire several gun salutes as part of Remembrance Day ceremonies.

The Royal Canadian Air Force will also conduct three flypasts over Ottawa-area ceremonies, including two CF-18 Hornets from 3 Wing Bagotville, Que., that will fly above the National War Memorial.