Prince Harry and Prince William are said to be no closer to mending their ongoing rift.

The battling brothers are both heading to Singapore to promote their causes, but royal watchers shouldn’t expect a heartfelt reunion anytime soon.

The Duke of Sussex stepped out in Tokyo on Wednesday for the ISPS Sports Value Summit-Special Edition alongside his pal Ignacio "Nacho" Figueras. The younger son of King Charles III is saddling up for the 2023 Sentebale ISPS Handa Polo Cup in Singapore Aug. 12. 

William is expected to visit the island republic in Southeast Asia Nov. 7 for the 2023 Earthshot Prize Awards ceremony.

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Prince Harry smiling wearing a navy blazer and a open button shirt

Prince Harry was in Tokyo Wednesday for the ISPS Sports Values Summit-Special Edition. (Reuters)

"I’m sure everybody managed those diaries to make sure there was no crossover whatsoever," True Royalty TV co-founder Nick Bullen told Fox News Digital. "Harry hasn’t even been going to old friends’ weddings. So, those moments where they might bump into each other aren’t happening, let alone the choreographed moments."

Prince William in a military suit marching in front of Prince Harry wearing a suit

Prince Harry's older brother Prince William is heir to the British throne. (Max Mumby/Indigo/Getty Images)

Bullen is an award-winning documentarian who has been producing programs about the British royal family for 20 years. He has also worked closely with the king for about a decade. His streaming platform is offering a new special dedicated to Balmoral Castle, where the royal family gathers every summer.

The castle, located in Scotland, was a refuge for Queen Elizabeth II and the known setting for her summer family gatherings. Britain’s longest-reigning monarch died there Sept. 8 at age 96.

Queen Elizabeth and Prince Charles wearing matching hunter green coats in front of sheep

Queen Elizabeth II is seen here with the former Prince Charles at Balmoral in 2021. (Andrew Milligan/Pool/AFP via Getty Images)

"William and [his wife] Kate [Middleton] are going to be spending time at Balmoral this summer," said Bullen. "They’re going to be staying up in a cottage that was a favorite of the queen’s when she was alive. William and Kate have taken it over with their children for this summer. So, it’s nice to see the traditions are continuing."

Prince William in a navy blazer and matching pants with a white shirt walking alongside his wife and their three children

Nick Bullen said the Prince and Princess of Wales will be heading to Balmoral this summer with their three children: Prince George, left, Princess Charlotte and Prince Louis. (Jonathan Brady/Pool/Getty Images)

It’s unclear whether Harry, 38 and his wife Meghan Markle have received an invitation to visit Balmoral this summer. Palace sources denied to the UK’s Daily Mail that the royal family was "snubbing" the Duke and Duchess of Sussex on the anniversary of the queen’s death. The insider told the outlet the king is preparing to spend the somber day "in quiet reflection."

Bullen claimed Charles, 74, is eager to make peace with his son and daughter-in-law.

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A close-up of a somber King Charles in his military uniform marching in front of Prince Harry wearing a suit with medals

True Royalty TV co-founder Nick Bullen claimed to Fox News Digital that King Charles III is eager to make peace with his son, Prince Harry. (Loic Venance/AFP via Getty Images)

"I’m told that the king continues to reach out to Harry and Meghan and that the door is always open," said Bullen. "I think, probably, he more than anybody, wants to repair the relationships. We all know things are still very tense between William and Harry, but I think the king does want to repair [things]. … There is probably an open invitation to visit the king whenever they can. And he would love to see them.

King Charles with his back turned being kissed on the cheek by Prince Harry

King Charles, being kissed on the cheek by his son Prince Harry, became monarch upon the death of his mother, Queen Elizabeth II, in September. (Matt Dunham/WPA Pool/Getty Images)

"Look, he’s the king," Bullen added. "He’s not going to be able to make it to California very often. They don’t have official roles. They don’t appear to have a 9-to-5 job. So, I would say they’ve probably got the ability to make a visit to Scotland should they wish, and I’m sure the king would have them there."

Markle, a former American actress, became the Duchess of Sussex when she married the British prince in 2018. In 2020, the couple announced they were stepping back as senior royals, citing what they described as the unbearable intrusions and racist attitudes of the British media. They moved to the wealthy, coastal city of Montecito that year. The couple sat for a two-hour TV interview with Oprah Winfrey, launched a six-part Netflix docuseries about their life together and Harry released his best-selling memoir "Spare."

Meghan Markle, Prince Harry, Prince William and Kate Middleton wearing formal wear on the buckingham palace balcony

The Duke and Duchess of Sussex are seen here with the Prince and Princess of Wales in 2018. Prince Harry and wife Meghan Markle stepped back as senior royals in 2020. (Max Mumby/Indigo/Getty Images)

Harry’s "His Royal Highness" title was noticeably gone from the royal family’s website Tuesday, more than three years after he and his wife made their exit. As part of the agreement made between the couple and the royal family in January 2020, Harry and Markle, 42, would no longer use their "HRH" titles after stepping back from their official positions. HRH titles are spoken and written in front of the names of princes and princesses and their spouses.

Prince William and Prince Harry wearing navy blazers and white shirts with ties walking almost next to each other

Prince William and Prince Harry's relationship has been strained since the Duke and Duchess of Sussex made their exit in 2020. (Daniel Leavl-Olivas/Pool/Getty Images)

William and Harry, who were once close, have been estranged since the couple made their royal exit. During the king’s coronation in May, the brothers were never seen speaking or even acknowledging each other. After the ceremony, Harry headed swiftly back to California.

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"I think there is so much water under the bridge between William and Harry that how they intend to find that common ground is beyond most royal commentators," Bullen explained. "I think there needs to be a brokerage from another person. There almost needs to be an intervention. It requires both parties to be willing to come to the table."

Prince Harry seen in the crowd during king charles coronation staring at his brother prince william who has his eyes closed

Prince William, Princess Charlotte; Prince Louis; Catherine, Princess of Wales; and Prince Harry, Duke of Sussex, during the coronation ceremony of King Charles III and Queen Camilla at Westminster Abbey May 6, 2023, in London. (Victoria Jones/WPA Pool/Getty Images)

"But I think it’s going to be very difficult to see how this is going to happen," Bullen admitted. "People have such entrenched views. [During] the coronation, the seating plan was carefully worked out [so] that they wouldn’t have to have an interaction. … I think it will require big apologies from both sides. But whether they’re going to come or not, I think it’s pretty unlikely."

Princess Diana in a white and navy dress with a matching hat standing next to Prince Harry and Prince William

Princess Diana died Aug. 31, 1997, at age 36. (Tim Graham Photo Library via Getty Images)

In January of this year, Harry made an appearance on "The Late Show with Stephen Colbert" to promote his memoir. During his conversation with the host, Harry admitted that if his mother Princess Diana were alive, the brothers wouldn’t have reached such a tumultuous point in their relationship.

"We wouldn’t have got to this moment," Harry said at the time. "It’s impossible to say where we would be now, where those relationships would be now, but there is no way that the distance between my brother and I would be the same."

Prince Harry and Prince William wearing matching navy blazers and white shirts with their backs turned against each other

According to Nick Bullen, an intervention will be needed to mend the rift between the battling brothers. (Dominic Lipinski/Pool/AFP via Getty Images)

Bullen agreed.

"I think the issue now is these are two men who are going to find it very difficult to move back beyond their entrenched positions," he said.

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In "Spare," Harry details his rivalry with William, 41, who is heir to the throne.

Prince Harry wearing a grey suit and blue shirt smiling sitting next to Stephen Colbert and his memoir Spare

Prince Harry made an appearance on "The Late Show with Stephen Colbert" on Jan. 10, 2023. (Scott Kowalchyk/CBS via Getty Images)

In the book, Harry alleged that during an argument in 2019, William called Markle "difficult" and "rude" and then grabbed him by the collar and knocked him down. Harry suffered cuts and bruises from landing on a dog bowl. Harry claimed Charles implored the brothers to make up. Following the funeral of Charles’ father, Prince Philip, in 2021, the king pleaded, "Please, boys, don’t make my final years a misery."

Neither Buckingham Palace, which represents the king, nor William’s Kensington Palace office commented on any of the allegations.

Author Katie Nicholl previously revealed in her book, "The New Royals," that even the late queen was "deeply hurt by Harry’s decision to leave his family and the country." Charles became king upon his mother’s death.

Prince Harry in a navy suit and tie holds Meghan Markles hand, wearing a dark dress after the Queen passed away

The Duke and Duchess of Sussex live in California with their son Prince Archie and daughter Princess Lilibet. (Chris Jackson/Getty Images)

"According to a friend, privately the queen confided that she was exhausted by the turmoil of their decision," Nicholl wrote. "She was very hurt and told me, ‘I don’t know, I don’t care, and I don’t want to think about it anymore,' says that person."

"It was a source of sadness to the queen that she got to see so little of [her grandchildren] Archie and Lilibet and that Harry and Meghan were not able to join her for a weekend at Balmoral in August [2022] when the queen used to host a ‘sleepover’ for all of her grandchildren and great-grandchildren," Nicholl said.

Another point of contention for the queen was the icy relationship between Charles and Harry, which allegedly "caused the queen so much upset." Nicholl also reported that the king "desperately wants to reconcile with his son."

The Associated Press contributed to this report.