Prince Harry, Meghan Markle's Olive Branch Rejected By Prince William, Kate Middleton: Report

Prince Harry and Meghan Markle returned to California from the U.K. without having spent any solo time with Prince William, Kate Middleton and their children, a report has claimed.

The Duke and Duchess of Sussex invited the Duke and Duchess of Cambridge and their three children — Prince George, 8, and Princess Charlotte, 7, and Prince Louis, 4 — to their daughter Lilibet's first birthday party at their U.K. home, Frogmore Cottage, in Windsor Saturday as an olive branch, Page Six reported, citing unnamed sources.

However, the Cambridges did not attend the birthday celebration, according to the outlet.

Prince William, Middleton and their two eldest children visited Cardiff Castle in Wales that day as part of the celebrations for Queen Elizabeth's Platinum Jubilee. Later that night, the Cambridge family attended the "Platinum Party at the Palace" concert in Buckingham Palace in London, which Prince Harry and Markle skipped.

"Things are still fraught — William is still wary of spending any time alone with Harry as you never quite know what may be reported back afterward," one U.K.-based insider claimed.

Prince Harry and Markle's children Archie, 3, and Lilibet, 1, didn't get to see their cousins before their family quietly left the U.K. Sunday and flew home to California, the report said.

However, Prince William and Middleton made sure to post birthday greetings for their niece on social media Saturday. "Wishing a very happy birthday to Lilibet, turning one today!" they tweeted.

Queen Elizabeth, Prince Charles and Camilla, Duchess of Cornwall also shared birthday wishes for Prince Harry and Markle's daughter via Twitter and Instagram that day.

Lili got to meet her great-grandmother twice during her U.K. visit, Page Six reported.

According to the outlet, the Sussex family's decision to leave the U.K. before the People's Pageant kicked off Sunday was always pre-planned and was not a snub to the Queen, who made another balcony appearance at the end of the celebrations with the Prince of Wales, Duchess Camilla, Prince William, Middleton and their kids.

Prince Harry and Markle attended two of the Jubilee events, including Trooping the Colour Thursday. They watched the Royal Air Force flypast from the Major General's Office, while the Queen and other members of the royal family appeared on the Buckingham Palace balcony.

The couple stepped out the following day to attend the National Service of Thanksgiving in honor of the Queen at London's St. Paul's Cathedral, where they were met with a mix of boos and cheers from the crowd that had gathered outside the church. After this outing, the Sussexes were not spotted in any other Jubilee event.

Prior to Prince Harry and Markle's U.K. trip, an unnamed insider told Page Six that Prince Charles' two sons had no plans to interact during the Queen's Platinum Jubilee celebrations.

"At the moment, it does not look likely that Harry and Meghan and William and Kate will meet up separately during the Jubilee celebrations," the source claimed. "There is certainly nothing in the diary at the moment."