Donald Trump's meeting with his 'friend' King Charles today may not have gone entirely to plan, after leaving Britain's most senior royal figure waiting for 21 minutes.

Mr Trump joined by his wife, US First Lady Melania, is taking part in his historic second state visit to the UK after being invited by the King following his second presidential win.

But things appeared to get off to a bumpy start, with the president running late for his meeting in the Walled Garden of Windsor.

The Trumps were due to touch down in the Marine One helicopter at 11.55am where they would be greeted by Prince William and Kate before meeting the King and Queen.

However, the visit's schedule appeared to go off the rails, with the helicopter landing at 12.14pm - 12 minutes after the Charles and Camilla arrived in their Bentley.