Prince Harry said the Covid pandemic has "flipped life upside down for so many" as he spoke at an event honouring those taking part in the Warrior Games.
The Duke of Sussex is taking part in a military event alongside US First Lady Jill Biden.
Harry, who spent 10 years in the Army, is co-hosting the virtual event honouring those taking part in the Warrior Games, which celebrates injured active duty and veteran US military service members.
Speaking at the event he said: "I am so sorry that we're not all together at the Warrior Games where we should be. The pandemic has certainly changed or flipped life upside down for so many people.
"I will never forget that first visit that I had to the Warrior Games, which inspired me to create the Invictus Games and the Invictus Games never would have been created had I not been inspired by every single one of you, and your companions, and the families for everything that you give to the service of this country.".
Harry appeared alongside Dr Biden, Secretary of Defence Lloyd Austin and Ken Fisher, CEO of Fisher House Foundation.
He is attending "in support of these athletes and their families".
The duke was expected to attend in person as the 2021 Warrior Games was slated to take this week in Orlando, Florida, but it was cancelled due to coronavirus-related concerns.
Harry, who founded the Invictus Games Foundation, which helps soldiers through their recovery via international sports competitions, served two frontline tours to Afghanistan.
A White House statement said the Warrior Games shares a "deep bond" with the Invictus Games.
Harry was inspired to found the global tournament after attending the Warrior Games in Colorado in 2013 and seeing how injured American military personnel thrived on the challenge of taking part in competitive sports that aided their recovery.
It celebrates the "resiliency and dedication of wounded, ill, and injured active duty and veteran US military service members".
Speaking at the start of the event, Dr Biden said: "Twenty years ago our world broke apart and the shockwaves of 9/11 continue today, but as the President and I visited the September 11 memorials this weekend I was reminded of the humanity that shined through the inhumanity of that day.
"There was a call to defend the values we hold dear as we waged a global war on terror and a courageous group of men and women stepped forward to say 'me, I will go'.
"And that includes you, Harry, you live by a simple principle, serve together, recover together."
The event is being livestreamed on YouTube.
