Prince Harry urged the country to stand "shoulder to shoulder" with its wounded veterans as he was presented with a humanitarian award for his efforts supporting injured servicemen and women.
Harry dedicated the honour to those who had been seriously injured fighting for Britain, declaring them "heroes" for paying a "terrible price to keep us safe and free".
But the Prince played down his efforts championing forces charities, saying: "Genuinely, I obviously don't feel that I have done nearly enough to deserve it."
The royal also accepted the award on behalf of his brother, the Duke of Cambridge, as through their joint foundation they have tackled the issue of caring for disabled and wounded servicemen and women.
Harry flew to Washington to receive the humanitarian honour from the Atlantic Council, a body which promotes transatlantic co-operation and international security, and he follows in the footsteps of U2 frontman Bono, who received the award in 2010.
Before the black-tie awards ceremony he met some of the "heroes" - a group of British servicemen and women who had competed at America's Warrior Games, an event for wounded service personnel.
The athletes won five gold medals and a bronze during the sporting event where injured veterans compete in Paralympic-style competitions.
Harry gave his acceptance speech after earlier receiving the distinguished humanitarian leadership award from retired general Colin Powell at an exclusive Washington hotel.
In his speech Harry, a serving army captain, said: "It would be wrong of me to speak for these heroes, but not presumptuous of me to pay tribute to them: so many of our servicemen and women have made the ultimate sacrifice; so many lives have been lost and so many changed forever by the wounds that they have suffered.
"They have paid a terrible price to keep us safe and free. The very least we owe them is to make sure that they and their brave families have everything they need through their darkest days - and, in time, regain the hope and confidence to flourish again. For these selfless people, it is after the guns have fallen silent, the din of battle quietened, that the real fight begins - a fight that may last for the rest of their lives."