Prince William continues to bear the strain of his relationship with his brother, Prince Harry, two years after the latter left the U.K. for a new life with Meghan Markle in the U.S.A.

Royal expert Duncan Larcombe told OK! magazine that "it's very clear to those that know William that the rift with his brother is not something that he can just forget about." He said that "it's very much, as you can imagine, a constant strain."

He believes that the Duke of Sussex feels the same way too, as he called the two brothers "as stubborn as mules." He said it must be hard for Prince Harry and Prince William to lose their once close bond, especially after what they went through together.

Larcombe explained, "These are brothers that glued together as they lost their mother, they went through that bereavement and as is quite clear, they dealt with it in different ways but they were very close. Every week the rift continues, Harry and William are the two people who are missing out the most."

He said it is "not great when two best friends and brothers fall out. If anybody knows what it's like to fall out with a best friend or a brother who was close to you when you were growing up, it's not nice. You miss them." Larcombe said "there is a lot of regret there" and thinks that the regret is felt on both sides.

The royal commentator claimed that the Duke of Cambridge must feel sad too without his brother's presence in his life.

"Everything else seems to be going right for William at this time, he's riding the crest of a wave in most aspects of his life, but sadly he has the absence of Prince Harry, his brother in his life," he continued as he explained that the Duke of Cambridge always knew where he would be in five years' time but never imagined that his relationship with his younger brother will end up as it is now.

"William's always had a set plan of where he wants to be in five years, how he's going to transition from prince to husband to father to future king. He's basically ticked all of those boxes that he set out to tick when he was graduating from university but the one thing not going right for him is something that is deeply upsetting," he said of the brothers' alleged rift. Larcombe remains hopeful that Prince William and Prince Harry will mend their relationship as he believes that "there'll always be a way back."

Meghan Markle, Prince Harry and Prince William
Prince Harry two years ago that he had grown apart from his older brother William Photo: AFP / Tolga AKMEN