Harry, an Apache helicopter pilot in the British military, told guests at the awards dinner that many servicemen and women have "paid a terrible price and 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 for the darkest days, and, in time, regain the hope and confidence to flourish again," Harry said.
Harry, 27, was being recognized along with his older brother Prince William for their charitable foundation's work. Harry, the third in line to the British throne after his father and brother, has worked with a number of charities. Those include Walking with the Wounded, a British charity that retrains and re-educates veterans, and Help for Heroes, which helps wounded servicemen and women.
Harry, who spoke for about five minutes, urged Americans and the British to work together to heal and support wounded veterans, pooling expertise and experience.
Former Secretary of State Colin Powell presented Harry with the humanitarian leadership award from the Washington-based think tank the Atlantic Council. Powell joked that Harry's presence meant that the average age for the annual awards dinner dropped 25 years.
The award doesn't come with any money; honorees get a glass globe trophy.
The annual award ceremony at the Ritz-Carlton Hotel also honored violinist Anne-Sophie Mutter, who received an artistic leadership award, and U.N. Secretary-General Ban Ki-moon, who accepted an international leadership award.
"I believe the United Nations can and must be the solution to the world's great challenges," Ban said.
Earlier in the day, Harry was at the British Ambassador's Residence to visit with wounded veterans who last week participated in Warrior Games, an athletic competition for injured military members. He also helped plant a tree in honor of his visit and in honor of his grandmother's 60 years as British monarch. Queen Elizabeth II is marking her Diamond Jubilee this year.
The Associated Press contributed to this report.