Officials are evaluating whether the incident will require any changes to be made to the schedule of the state visit, which starts on Monday.

A Buckingham Palace spokesperson said in a statement: "His Majesty is being kept fully informed of developments and is greatly relieved to hear that the President, First Lady and all guests have been unharmed. As you would expect, a number of discussions will be taking place throughout the day to discuss with US colleagues and our respective teams to what degree the events of Saturday evening may or may not impact on the operational planning for the Visit."

It is understood that the King and Queen reached out privately to The President and First Lady to express their sympathies with all those affected on the night and their gratitude to the security services who prevented further injury.