Britain's Prince Harry speaks during the opening ceremony for the Invictus Games in Toronto, Ontario, Canada September 23, 2017.

Spectators cheer for Team Canada during the opening ceremony of the Invictus Games in Toronto, Canada September 23, 2017.

Britain's Prince Harry speaks to athletes at the Toronto Pan Am Sports Centre ahead of the Invictus Games in Toronto, Ontario, Canada, September 22, 2017.

Team USA take part in the opening ceremony of the Invictus Games in Toronto, Canada September 23, 2017.

Patron of the Invictus Games Foundation, Prince Harry greets people outside CAMH The Centre for Addiction and Mental Health which he visited today prior to the opening of the Invictus Games this evening in Toronto, Ontario, Canada, September 23, 2017.

Canada's Prime Minister Justin Trudeau (L) and Britain's Prime Minister Theresa May (C) watch Steve Arnold, Britain's vice-captain for the Invictus Games, during an event at Lisgar Collegiate Institute in Ottawa, Ontario, Canada, September 18, 2017.

Canada's Prime Minister Justin Trudeau takes part in the opening ceremony of the Invictus Games in Toronto, Canada September 23, 2017.

Canada's Prime Minister Justin Trudeau takes part in the opening ceremony of the Invictus Games in Toronto, Canada September 23, 2017.

Britain's Prince Harry speaks to an athlete at the Toronto Pan Am Sports Centre ahead of the Invictus Games in Toronto, Ontario, Canada, September 22, 2017.

Britain's Prince Harry meets with Canada's Prime Minister Justin Trudeau ahead of the Invictus Games in Toronto, Ontario, Canada, September 23, 2017.

Ukrainian President Petro Poroshenko (first row, L) and his wife Maryna Poroshenko, Canadian Prime Minister Justin Trudeau (first row, R) and his wife Sophie-Gregoire Trudeau, U.S. first lady Melania Trump (second row, L) and Britain's Prince Harry (second row, second from L), Governor General of Canada David Johnston (second row, second from R) and his wife Sharon Johnston applaud during the opening ceremony for the Invictus Games in Toronto, Canada, September 23, 2017.

Ukrainian President Petro Poroshenko (first row, L) and his wife Maryna Poroshenko, U.S. first lady Melania Trump (second row, L) and Britain's Prince Harry (second row, second from L), attend during the opening ceremony for the Invictus Games in Toronto, Canada, September 23, 2017.

Members of the Iraqi delegation march in during the opening ceremony for the Invictus Games in Toronto, Canada, September 23, 2017.

Performers dance during the opening ceremony for the Invictus Games in Toronto, Canada, September 23, 2017.