Drone flights above central London and Windsor have been banned while president Barack Obama is visiting the city.
Restrictions imposed by the Civil Aviation Authority (CAA) say that as part of the "overarching security plan" flights by drones and other aircraft below 2,500 feet (762m) will not be allowed over large parts of London.
Usually drones are permitted to 400 feet (122m) but face restrictions when flying above crowds or near airports.
Over the period of April 21 to April 24 aircraft – other than emergency vehicles or those going to airports – will be prohibited.
"Any small balloon, any kite weighing not more than two kilograms, any small unmanned aircraft and any parachute including a parascending parachute," will fall under the restrictions, according to the CAA.
The restrictions will extend from Purley in the south to Haringey in the North of London and will also be in place over Windsor when Barack and Michelle Obama visit the Queen.
The president and first lady are visiting the UK to meet prime minister David Cameron, visit the Queen and participate in a town hall meeting. Obama is expected to use this meeting to urge the UK to stay in the European Union.
Flight restrictions are common for major events to protect the security of those attending. In the US a no-fly zone of 32 miles was introduced for drones around the time of the Super Bowl.
Earlier this month a drone collided with a plane landing at London Heathrow on April 17. The British Airways flight was not damaged in the collision but an investigation has been launched in an attempt to locate the drone and its pilot.