Britain's Prince William is reportedly "worried" about his younger brother Prince Harry after he spoke about his mental health and struggling with the pressures of his life in an interview with ITV.

Prince Harry gave a revealing interview during the ITV documentary Harry & Meghan: An African Journey in which he and his wife Meghan Markle said they struggle with the intense scrutiny from elements of the British tabloid press.

The British royal also admitted that he and Prince William "are certainly on different paths at the moment" and said they have "good days" and "bad days".

The BBC has now reported that a Kensington Palace source told them that Prince William is "worried" about his brother and hopes the Duke and Duchess of Sussex "are all right".

The palace source added that there is a view that the couple are "in a fragile place" and suggested there is a "mood of concern for the safety" of the Duke and Duchess of Sussex.

Prince Harry commented on the rumours of a rift between him and Prince William in the documentary which followed him and Markle on their tour of southern Africa earlier this month.

The speculation of a falling out between the royals was prompted when he and Markle split from their joint charity with Prince William and Kate Middleton, the Duke and Duchess of Cambridge, earlier this year.

He said: "We are brothers. We will always be brothers. We are certainly on different paths at the moment but I will always be there for him as I know he will always be there for me.

"We don't see each other as much as we used to because we are so busy but I love him dearly. The majority of the stuff is created out of nothing but as brothers, you know, you have good days, you have bad days."

In the documentary, Prince Harry described the way he deals with the pressures of his life as being a matter of "constant management".

"Part of this job, and part of any job, like everybody, is putting on a brave face and turning a cheek to a lot of the stuff, but again, for me and again for my wife, of course there is a lot of stuff that hurts, especially when the majority of it is untrue," he said.

"But all we need to do is focus on being real, and focus on being the people that we are, and standing up for what we believe in. I will not be bullied into playing a game that killed my mum."

Meanwhile, Markle spoke about the struggles of becoming a mother to their five-month-old son Archie while living under the glare of the media spotlight in the programme.

"Not many people have asked if I'm OK. But it's a very real thing to be going through behind the scenes", she told ITV's Tom Bradby.

Asked if it would be fair to say it had "really been a struggle", Meghan replied: "Yes."

The former Suits star said that adjusting to royal life had been "hard".

"When I first met my now-husband my friends were really happy because I was so happy," she said.

"But my British friends said to me, 'I'm sure he's great but you shouldn't do it because the British tabloids will destroy your life'."

The Duke and Duchess have both brought separate legal actions against parts of the press, with Meghan suing the Mail on Sunday over a breach of privacy when it published a private letter between her and her estranged father.

Harry later filed his own proceedings at the High Court in relation to the alleged illegal interception of voicemail messages by Sun, News of the World and Daily Mirror journalists.