Prince Harry has hosted a party to welcome wounded servicemen and women to the UK ahead of the opening ceremony of the inaugural Invictus Games.
He thanked competitors for embracing the games “so enthusiastically”, while US president Barack Obama also wished teams well in a video message.
More than 400 competitors from 13 countries will take part in the first Invictus Games over four days.
Queen Elizabeth Olympic Park will host the opening ceremony later.
The competition is the brainchild of Prince Harry with competitors – many with missing limbs or other serious injuries – due to compete for medals in nine different adaptive sports.
The sports include athletics, wheelchair basketball and rugby, sitting volleyball, archery, powerlifting, swimming, indoor rowing and road cycling.
The name of these games comes from the poem Invictus, published in 1888 by William Ernest Henley.
He was an amputee himself. Invictus means unconquered and it is clear to see why this is so relevant to the hundreds of competitors descending on the Olympic park this week.
The British Armed Forces team is made of more than 100 determined men and women whose lives have been changed by war.
Some have lost limbs, some have suffered long term injuries, others are struggling with the mental scars of the conflicts they have experienced.
But, from the athletes I have spoken to, these games have given them that focus, that drive to succeed.
They’re pragmatic, realistic about their future – to quote one of the competitors, Josh Boggi who lost three limbs in an explosion back in 2010, the hardest thing for him is chopping onions. And don’t dare call him a hero.
The prince hosted the party for competing teams, their families and supporters at the US ambassador’s official residence, Winfield House, in London’s Regent’s Park.
He thanked teams for “coming all this way”, adding: “You really have no idea what you’ve let yourselves in for.”
In a video message to athletes at the party Mr Obama also paid tribute to the teams, telling the competitors “Your incomparable souls inspire us today”.
“I know it’s going to be a fiercely competitive few days, but the truth is that everyone of you in these games, every service member and veteran, has already earned our highest admiration and our deepest gratitude,” the president said.
American rock band Foo Fighters entertained guests at the party.
A Kensington Palace spokesman said the Duchess of Cambridge, who is pregnant with her second child, will not attend the opening ceremony of the games on Wednesday or the athletics event on Thursday.
She is suffering from acute morning sickness and her attendance on the forthcoming visit to Malta will be kept under review, with a decision to be taken closer to the time.
Defence Secretary Michael Fallon said the arrival of the Games was a momentous day for the British team.
“They are testament to the excellent care and support that is available through our world-renowned defence rehabilitation process,” he said.
“Our Armed Forces have played a major role in making the Games happen – not just our inspiring competitors but also the 500 service personnel in a wide range of roles who will be supporting their comrades.”
Earlier, the games chairman Sir Keith Mills, a former deputy chairman of the London Organising Committee of the Olympic and Paralympic Games, praised Prince Harry for his “enthusiasm”, saying the games “would not have happened without his support”.
He also said it would not be a “one off” and that other countries had expressed an interest in playing host in future.
Prince Harry said he hoped his position had helped to promote the popularity of the event – the opening ceremony for which begins at 18:30 BST on Wednesday at the Queen Elizabeth Olympic Park.
The “I AM” logo of the Invictus Games – based on a similar idea in the US known as the Warrior Games – will be projected on to the front of Buckingham Palace for the duration of the competition.
Invictus in numbers
8 – percentage of the British team in the RAF
9 – number of sports included in the Games
13 – number of nations taking part
23 – percentage of the British team in the naval service
42 – percentage of the British team who are still serving members of the armed forces
69 – percentage of the British team in the Army
131 – number of people in the British armed forces team.
400 – approximate number of participants in the Games
5,000 – number of spectators who will watch the opening ceremony