The Field of Remembrance at Westminster Abbey pays tribute to those who have died since WWI Millions of people are expected to observe a two-minute silence at 1100GMT to mark Armistice Day.
Ceremonies will take place across the UK to honour all who have fallen since WWI, including the 110 servicemen killed in Afghanistan in the past year.
In London, a service will be held for the 90th time at the Cenotaph memorial.
Meanwhile, David Cameron has layed a wreath at the site of the Army’s bloodiest battle since the end of WWII – at the Imjin River in South Korea.
Some 59 men from the 1st Battalion, Gloucestershire Regiment, died and 526 were captured when they were cut off by vastly superior Chinese Communist forces during the Battle of the Imjin River in the Korean War in 1951. Another 34 men died in captivity.
The British soldiers succeeded in delaying the advance of the Communist troops, preventing them from outflanking the forces of the Republic of Korea and the UN, who were then able to prevent a direct assault on the capital Seoul.
The prime minister, who is in the country for a G20 summit, spent several moments in contemplation at the memorial in what is now known by Koreans as Gloster Valley.
On Wednesday evening, British journalists who have died reporting conflicts around the world were honoured for their bravery in a memorial service attended by the Duchess of Cornwall.
The duchess joined families of reporters and cameramen killed over the last decade to commemorate their sacrifice “in the pursuit of truth”.
A host of media figures packed into St Bride’s church, on Fleet Street, the former home of many of Britain’s national newspapers, for the ceremony of remembrance.
On Tuesday, the first remembrance field dedicated to the British servicemen and women killed in Afghanistan was opened by Prince Harry.
The prince also planted a cross in the Royal British Legion Wootton Bassett Field of Remembrance, at Lydiard Park, Wiltshire.
The 342 UK service personnel who have lost their lives in the conflict were honoured with a two-minute silence.
Up to 35,000 crosses will be planted, each with a personal message.
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