A US flight travelling from Paris to Washington has been forced to make an emergency landing in London after declaring a mid-air emergency.

United Airlines Flight UA914 was diverted shortly after it flew over Cornwall and touched down in London’s Heathrow airport at 1.35pm this afternoon.

A Heathrow spokesperson confirmed to The Independent that the Boeing 767-300 had landed safely.

The flight left Paris’s Charles De Gaulle airport at 12.24pm but was diverted due to a "maintainence issue," the told The Independent.

The Mirror and City AM reported the aircraft declared a mid-air emergency, known as a 7700 squawk, at around 1.10pm. It was due to land in Washington at 3pm local time.

The Boeing 767-300 was carrying 209 passengers and a crew of 10. The aircraft is currently being inspected by maintainence staff.