It has been months since Prince Harry and Meghan Markle's son Archie Harrison met his grandfather Prince Charles in person, but they stay connected through video calls.

This was evident in a recent royal Zoom call as Archie called Prince Charles 'pa,' leaving the heir apparent delighted with the sweet gesture of the young royal, reports The Sun.

According to the report, Prince Harry and Meghan Markle held a video chat with Harry's father Prince Charles, and grandmother Queen Elizabeth II on the occasion of his 36th birthday last week. The couple's one-year-old son was also present for the virtual birthday celebrations and kept the royals engaged with his antics. The little one even helped his father blow out his birthday candles on the cake Meghan had baked at home.

A source said about the call: "It was very pleasant. Harry told the family how much he missed them. Meghan baked a cake and Harry blew out candles. Archie made them laugh when he also blew them out."

The insider further claimed that the 16-month-old, who started comprehending words a few months ago, delighted the Prince of Wales by calling him 'pa,' short for grandpa. It was earlier reported in Us Weekly in June that Archie has started speaking a few words like 'Dada,' 'Mama,' 'book,' and 'dog.'"

Though the video call was a heartwarming moment for Charles, it is reported that Prince William and Kate Middleton were missing from the family call with the Sussexes amid reports of a feud between the royal siblings. The source said: "It was a bit awkward that William and Kate weren't there."

Meanwhile, a source told the Mirror: "William sent his birthday best wishes. There was some excuse made about why he wasn't there."

The Duke and the Duchess of Cambridge had wished Harry on his birthday on Tuesday through their social media accounts. Sharing a picture of themselves and Harry racing at a Heads Together relay at London's Olympic Park in 2017, they had written: "Wishing a very happy birthday to Prince Harry today!"

Prince Harry, Meghan Markle and Archie
An official christening photo released by Prince Harry and his wife Meghan, holding their baby son, Archie at Windsor Castle SUSSEXROYAL / Chris ALLERTON

On the day, the Cambridges were spotted on public royal engagements as well. The royal couple was seen making bagels at the famous 24-hour Beigel Bake on London's Brick Lane which was forced to shut during the coronavirus crisis.