Meghan Markle, Prince Harry made the Queen a promise about Archie, Lilibet

Prince Harry and Meghan Markle have yet to personally introduce their daughter Lilibet Diana to the British royals. However, they had reportedly assured Queen Elizabeth II that this would happen soon.

The Duke and Duchess of Sussex reunited with Her Majesty, Prince Charles, and Camilla last week on Thursday at Windsor. The couple paid the royal family a visit ahead of their trip to the Netherlands for the Invictus Games.

A source told the Mirror that the couple made the decision to visit the U.K. "several weeks ago." Prince Harry had told his grandmother about it in a phone call prior to Prince Philip's memorial on March 29. The insider claimed, "There is very much a willingness as much as possible for everyone to come together for the Queen."

Another source said that the Duke and Duchess of Sussex had "incredibly warm and good-natured" and "very cordial" meetings with the family. They also promised Queen Elizabeth II that they would return soon with their children, Archie, 2, and Lilibet Diana.

Prince Harry and Meghan Markle are believed to be aware of the Queen's recent health scares. As such, they want her to be able to spend time with her great-grandchildren from across the pond.

"Both the Duke and Duchess are very mindful that Queen is getting older and has had health issues associated with her great age. They have made it clear they are certainly planning to return to see the Queen with their family in the near future," the source said.

It has been over a year since the royal family saw Archie, who is now two years old. They last saw him when he was 10 months old. They have yet to meet Lilibet although it is understood that the Duke and Duchess of Sussex already introduced her to the family via video calls.

Expectations are high for Prince Harry and Meghan Markle to join in the Platinum Jubilee celebrations in June with Archie and Lilibet. Their daughter's first birthday on June 4 also happens to fall on the same week as the four-day bank holiday on June 2-5. The source said that "it's certainly a possibility the Duke and Duchess could attend the celebrations."