London, UK - Britain's Prince Harry has said he hopes to "draw a line" under past battles, including with his family, and wants to work things out with his cancer-afflicted father, King Charles III, and estranged brother, Prince William.

In an interview with GQ magazine recorded last month but released on Tuesday, Harry also revealed his guilt over his last phone call with his mum, Princess Diana.

Harry, known as the Duke of Sussex, said he was "optimistic" after he and his wife, Meghan Markle, and two young children relocated to Britain in August in a surprise move after six years living abroad.

"There is, you know, some battles that have been fought, necessarily so, but hopefully we can all draw a line under that," he told GQ in an interview recorded in New York.

"With everything else that's going on in the world, there's aspects of the past that I'm sure all of us – me, my family, some of the British press – that we'd all like to leave that behind us and work for the greater good."

Harry and Meghan returned to Britain after stepping down as working royals in 2020, amid a major rift with his family.

They have enrolled their children, Prince Archie and Princess Lilibet, in a British school believed to be in the rural Cotswolds area where they are thought to be living.

Harry confirmed the family moved back for the "opportunities" it presented, adding that giving the children a taste of British schooling "meant a lot to me".

He said he had also wanted to "be back closer to my family and to be back on UK soil for longer than a few days or a week here or there".

Harry insisted he wanted things to "work out" with his 77-year-old father, who is being treated for an undisclosed cancer, and brother William, heir to the British throne and from whom he remains estranged.

"The most important thing is to reconcile," he said, adding: "Scars stick around forever".

Last week Harry and Meghan were greeted by crowds of well-wishers on their first joint public appearance since their return.

"I'm hopeful," the prince added. "I'm not naive... And I think a large part of this is about respect as well.

"Our position is really quite clear now. And hopefully we can get on with life."

He noted that he had had years of therapy after his mother, Diana, was killed in a Paris car crash in 1997 when he was just 12.

Harry told GQ: "One of my biggest regrets is that last phone call I had with her," explaining he had just wanted to run off to play with his cousins.

"If I'd known it was the last call with her, how different that conversation would be," Harry said.

The "guilt and stuff that just really stuck with me. It was like heavy".