Prince Harry met with staff and patients at a Toronto mental health facility also visited by his late mother Diana, hours before the opening ceremony of the third Invictus Games Saturday.
The British royal was scheduled to officially open the games -- for disabled or wounded soldiers and veterans -- alongside US First Lady Melania Trump and Canadian Prime Minister Justin Trudeau late Saturday.
"The Invictus Games are a unique and powerful way to honor those who have sacrificed so much on behalf of their country," Prime Minister Trudeau said.
Prince Harry and Melania Trump -- dressed in a houndstooth suit -- spoke for a few minutes in the afternoon, posing for photographs before the prince headed to give out the first medals of the Games at the driving challenge competition.
Prince Harry, dressed in a blue blazer and beige pants, spent some time with athletes, as he did on Friday, following a tour of Toronto's Center for Addiction and Mental Health, where Diana visited 26 years ago.
The prince, who was not joined by girlfriend Meghan Markle, met hospital staff and young patients before greeting fans and posing for pictures outside.
Hours before the opening ceremony, speculation mounted over whether the British royal would arrive at the event with Markle.
Since the "Suits" actress, 36, told Vanity Fair the couple are "in love" in an interview published early this month, fans and the press have been eagerly awaiting an official appearance.
According to his schedule, Queen Elizabeth II's grandson plans to stay at Markle's Toronto home for the entire eight days of the Games.
After last year's Games in Orlando, Florida, the third edition of the Games in Toronto brings together more than 550 injured soldiers and veterans from 17 countries.
The first Invictus Games, based on the Paralympic Games, were held in September 2014 in London. They were launched by Prince Harry, who served with the British Army in Afghanistan.
This year's Games are taking place in Canada, which is marking the 150th anniversary of the founding of its confederation and the centenary of the Battle of Vimy during World War I.
Performances by Canadian pop artists Sarah McLachlan and Alessia Cara and British soprano Laura Wright were set for the opening ceremony.
Meanwhile, American rocker Bruce Springsteen will headline the closing ceremony on September 30, joined by Bryan Adams and Quebecois artist Coeur de Pirate.