Prince Harry gives Invictus Games medal won by U.S. Army sergeant to hospital staff in London

When U.S. Army sergeant Elizabeth Marks received a gold medal for winning the 100-meter freestyle at the Invictus Games last month in Orlando, she handed it back to Prince Harry and asked that he deliver it to the hospital staff in London who she says saved her life in 2014.

On Wednesday, England's royal prince followed through.

"From all of us, it's just a huge, huge thank-you to all of you," Prince Harry told the team at Papworth Hospital in Cambridgeshire.

Two years ago at the inaugural Invictus Games in London, Marks, 25, went into respiratory distress. She credits the medical team at Papworth for saving her life.

In interview last month with ABC's Bob Woodruff, Marks explained why she wanted Prince Harry to return the medal to England.

"I gave it to him so that he could help facilitate in getting it to Papworth Hospital, the people who saved my life," she said. "It was premeditated, we had spoken on a different occasion about me wanting to give it to them as a token of gratitude because how do you say thanks to the people that saved your life?"

Marks is an active sergeant in the U.S. Army and is on the 2016 U.S. Paralympic swimming team.She sustained bilateral hip injuries while on tour in Iraq and had four surgeries in 18 months.