Meghan Markle has said she has "the two best guys in the world" as she and Britain's Prince Harry introduced their firstborn child to the world.

Buckingham Palace this afternoon confirmed the baby boy's name as Archie Harrison Mountbatten-Windsor.

The newborn has met his great-grandparents - Britain's Queen Elizabeth and Prince Philip - as well as grandmother Doria Ragland, who has flown into the UK from Los Angeles.

The Queen and The Duke of Edinburgh were introduced to the newborn son of The Duke & Duchess of Sussex at Windsor Castle. Ms Doria Ragland was also present. The Duke & Duchess of Sussex are delighted to announce that they have named their son Archie Harrison Mountbatten-Windsor. pic.twitter.com/PaHVhPlUl5

— The Royal Family (@RoyalFamily) May 8, 2019

Earlier, the couple showed off their new son to waiting cameras inside at Windsor Castle - the first time the family have been seen together since Meghan gave birth on Monday.

Harry carried the infant out for the press to see him, telling reporters the couple were "so thrilled to have our own little bundle of joy".

Britain's Prince Harry and Meghan Markle during a photocall with their newborn son in St George's Hall at Windsor Castle, England | Image: Dominic Lipinski/AP/Press Association Images

Meghan said: "It's magic, it's pretty amazing, and I have the two best guys in the world so I'm really happy.

"He has the sweetest temperament, he's really calm and has just been a dream. It's been a special couple of days."

Harry joked that his son has "already got a little bit of facial hair" as he spoke of his excitement at becoming a father.

He said: "His looks are changing every single day.

"Parenting is amazing. It's only been two or three days and we're so thrilled to have our own little bundle of joy."

Britain's Prince Harry and Meghan Markle during a photocall with their newborn son in St George's Hall at Windsor Castle, England | Image: Dominic Lipinski/AP/Press Association Images

As for who he takes after, Meghan said the couple were "still trying to figure that out".

Baby Archie - believed to be the first mixed-race child born to a senior member of the British royal family in centuries - is seventh in line to the throne.

Despite the possibility that he does end up as British monarch one day, the infant will not be made a prince unless his great-grandmother steps in.

The new royal was born in the early hours of Monday morning and has spent his time since then resting with his parents at cottage home near Windsor Castle.