Harry appeared at the event to present Pittsburgh Steelers defensive tackle Cameron Heyward with the Walter Payton Man of the Year Award - the biggest honour of the night.

It comes after Harry flew thousands of miles from his Californian home to be at the King's side on Tuesday.

He met with his father for around 45 minutes at Clarence House, where the King had been recovering after receiving treatment.

Harry did not see his brother Prince William - or his sister-in-law Kate, the Princess of Wales, as she recovers from planned abdominal surgery - and returned to the US on Wednesday.

The brothers have had a fractured relationship for a number of years following Harry's departure from royal duties in early 2020 to live in the US with his wife Meghan and their two children, four-year-old Archie and Lilibet, aged two.

Since their move to America, the Duke and Duchess of Sussex have been critical of the Royal Family in TV interviews, including Harry's book Spare, which was published last year.

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Harry appeared in public for the first time since his father's diagnosis on Thursday night at the NFL awards ceremony, and while introducing the award joked the United States "stole rugby from us and you made it your own".

"Instead of passing it backwards, just pass it forwards," he said. "Why not wear pads and a helmet?

"All kidding aside, what you guys do on and off the field is truly remarkable. You are role models for millions in the way you carry yourselves and the way you give back.

"This final award, the highest honour, is all about serving your community, and there is one special man we'd like to pay tribute to now."

As Heyward received the award, he hugged the duke and said: "Prince freakin' Harry, I'm just shocked, that's Prince Harry."

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The 34-year-old created the Heyward House Foundation, which supports several initiatives in the Pittsburgh area.

The award recognises a player who has achieved on and off the field and made a positive impact on their community.

The winner is awarded $250,000 (£198,000) to donate to a charity of their choice.