The King and Queen have led a two-minute silence to mark the 80th anniversary of VJ Day.
Charles and Camilla have joined the Prime Minister Sir Keir Starmer at a national service of remembrance at the National Memorial Arboretum in Staffordshire.
Some 33 veterans aged between 96 and 105 who served in the Far East and Pacific are also attending the event as guests of honour.
The King, Queen and Prime Minister laid wreaths and floral tributes at a memorial ahead of a national two-minute silence at noon.
Camilla was seen wearing a white pleated chiffon dress by Dior and a white Philip Treacy hat as she paid tribute. Alongside her outfit, the Queen wore The Rifles brooch, of which Her Majesty is Colonel-in-Chief.
The Red Arrows joined historic Spitfire and Hurricane aircraft for a flypast over the commemorations.
Charles had earlier hailed the “courage and camaraderie” of heroes who fought in the Pacific and Far East in “humanity’s darkest hour” as “a flame that shall blaze for eternity” during a six-minute address.
The King also significantly acknowledged the devastation caused by the atomic bombing of Hiroshima and Nagasaki which led to Japan’s surrender, describing the “immense price” on its citizens as one “we pray no nation need ever pay again”.
His reflection on the nuclear attacks, which paved the way for the end of the Second World War, comes at a time of increased concern about the global threat of nuclear conflict.
In an audio message to the nation, realms and Commonwealth, the King spoke of the horrors faced by allied prisoners of war “who endured years of brutal captivity: the starvation, disease and cruelty that tested the very limits of human endurance”, and the “mental and physical scars” the war left on those who survived.
And he vowed the service and sacrifice of VJ Day heroes “shall never be forgotten”, telling their families and the “sadly dwindling band of veterans”: “Please know that the courage and camaraderie displayed in humanity’s darkest hour is a flame that shall blaze for eternity – a beacon that honours our past and guides our future.”
The King, in what is believed to be the most direct reference by a British monarch to the suffering in Hiroshima and Nagasaki, said it was right to pause and acknowledge the impact of the “war’s final act” on the people of the Japanese cities.
“Innocent civilian populations of occupied territories faced grievous hardships, too,” he said in the broadcast released at 7.30am on Friday.
“Their experience reminds us that war’s true cost extends beyond battlefields, touching every aspect of life – a tragedy all-too vividly demonstrated by conflicts around the world today.
“On this landmark anniversary, we should also pause to acknowledge that in the war’s final act, an immense price was paid by the citizens of Hiroshima and Nagasaki – a price we pray no nation need ever pay again.”
He added: “But in recalling so much suffering, we must not lose sight of how great was the cause and how sweet the victory.”
VJ Day on August 15 marks the anniversary of the end of World War Two.
Much of the celebration in 1945 focused on VE (Victory in Europe) Day in May, with those who served in the Far East labelled The Forgotten Army.
By 1945, some 365,000 British and 1.5 million Commonwealth troops had been deployed across Asia and the Pacific.
More than 90,000 British troops were casualties in the war against Japan, and nearly 30,000 died, while more than 12,000 Britons were among the 190,000 Commonwealth troops held as Prisoners of War by the Japanese.
Of the Allied forces, the US suffered the greatest losses, with more than 100,000 killed in action.
In Hiroshima and Nagasaki, more than 200,000 people were killed by the US bombs and in the months after succumbing to radiation sickness, the effects of burns and other serious injuries.
The King described the 80th anniversary as a day of “profound remembrance” and said of his grandfather King George’s VI’s “The war is ended” audio broadcast at the time: “Seldom can a simple message have resonated with such a potent mix of relief, celebration, and sorrow for those who never lived to see the glow of freedom’s new dawn.”
He also painted a vivid picture of when “high above those monsoon-lashed jungles, allied pilots displayed their own fearless bravery, flying fighters, bombers and transport aircraft into enemy fire and nature’s fury”.
The speech made no mention of the King’s father Prince Philip, the late Duke of Edinburgh, who was in Tokyo Bay on board the destroyer HMS Whelp, a warship he served on as second-in-command, when Japanese officials formally signed the surrender on the USS Missouri on September 2 1945.
But Charles paid tribute to his mentor and great uncle Earl Mountbatten, who oversaw the defeat of the Japanese offensive towards India as Supreme Allied Commander South East Asia Command.
The Prince and Princess of Wales also reflected on the “enduring debt” owed to those who fought.
In a message posted on social media, signed “W & C”, they said: “Today, on the 80th anniversary of VJ Day, we remember the courage, sacrifice and resilience of all who served. Today we especially think of those British and Commonwealth troops who fought in the Asia-Pacific.
“We owe an enduring debt to the generation who gave so much, and to whom we will always be grateful. Lest we forget.”
