Donald Trump's helicopter was forced to make an emergency landing on Thursday with the US President and the First Lady on board.
The Marine One helicopter was flying to Stansted Airport from the Prime Minister's estate at Chequers when it suffered "a minor hydraulic issue".
White House Press Secretary Karoline Leavitt said the aircraft made the emergency landing "out of an abundance of caution".
She added that Mr Trump and his wife Melania "safely boarded the support helicopter" and continued on to Stansted where they "were able to board Air Force One for the return journey from the UK".
Photos from Luton Airport show emergency services and armed police on the tarmac and the presidential helicopters, Marine One and Marine Two, just off the runway.
The two aircraft, both of which are specially adapted, are known as "white tops" because of their livery.
For security reasons, they often fly within a group of identical helicopters which act as decoys.
They are also fitted with radar jamming systems and missile defence and contain electronics which are designed to withstand the electromagnetic pulse of a nuclear blast.
PICTURED: Marine One landing at Chequers, near Aylesbury
|PA
PICTURED: Donald Trump arriving at Chequers to meet with the Prime Minister
|PA
Marine One had been being used by the President to travel between locations during his State Visit.
The US President has this week undertaken an unprecedented second State Visit to the UK, something no other President has received.
Mr Trump had been at Chequers for a joint press conference with Sir Keir Starmer.
The pair covered a number of topics including Palestine, free speech and the ongoing migrant crisis.
They also signed a historic Tech Prosperity Deal.
DONALD TRUMP'S STATE VISIT - READ MORE:
Donald Trump and Sir Keir Starmer signed a historic tech prosperity deal during the President's State Visit
|PA
The President attended a state banquet at Windsor Castle alongside the royal family
|PA
Other events during the State Visit included the President laying a wreath at the grave of Queen Elizabeth II, attending a royal carriage procession in Windsor, and participating in a state banquet alongside the royal family.
During his toast, Mr Trump hailed the second State Visit as "one of the highest honours" in his life, and praised the Prince and Princess of Wales.
However, the President's time in the UK was not without protest.
Images of the 79-year-old alongside Jeffrey Epstein were projected onto Windsor Castle before his arrival on Tuesday.
Thousands gathered in London to protest against Donald Trump during his State Visit
|PA
On Wednesday thousands attended demonstrations against the US President in London, including former Labour leader Jeremy Corbyn.
Chants of "no to Trump" could be heard around Parliament Square during the march organised by the Stop Trump Coalition.
Our Standards: The GB News Editorial Charter