Services of commemoration are being held around the world to mark the end of World War I in 1918.
Angela Merkel has become the first German chancellor to mark Armistice Day by attending the main French commemorative event in Paris. In London, the Queen, politicians and armed forces chiefs will mark the passing of the WWI generation.
Australia has already held remembrance services, and later the US will hold Veterans Day events. Australia's east coast is 11 hours ahead of GMT, and so was one of the first places to commemorate the 11th hour of the 11th day of the 11th month - the time the guns of World War I fell silent.
The names of five Australian soldiers killed in Afghanistan since Remembrance Day last year were being added to the roll of honour at the Australian War Memorial in the nation's capital, Canberra, Australian television reported.
At the main UK military base in Afghanistan, Camp Bastion in Helmand province, a padre led prayers for the dead and injured in all conflicts since World War I.
The BBC's Adam Mynott reports a heavy gun was fired, and for two minutes those who could stood still in silence to pay respects for those killed in war.
He added that at the forefront of people's minds were the 233 British service personnel who had died in Afghanistan since military operations began in 2001.
French President Nicolas Sarkozy and the German chancellor rekindled the flame on the tomb of the unknown soldier at the foot of the Arc de Triomphe in Paris in a symbolic move designed to signal a new era in Franco-German relations.
The two leaders also observed a silence, flanked by soliders from a Franco-German brigade and officers from both countries' armed forces.
The memorial service in London, at Westminster Abbey, is being held following the deaths this year of the final three veterans of the war living in the UK.
But the last surviving British World War I veteran shunned Remembrance Day commemorations in Australia because he was against the glorification of war, his family has said.
Claude Choules, 108, who lives in a nursing home in Perth, became Britain's sole survivor from the 1914-to-1918 war following the death of fellow veteran Harry Patch at the age of 111.
Wednesday's service at Westminster Abbey will coincide with the ritual two-minute silence that marks the end of WWI and pays respect to all war dead.
Relatives of World War I veterans will give readings, and a Royal Marines bugler is to sound the Last Post. The Queen is to lay a wreath on the Grave of the Unknown Warrior.
