Drones have been banned from large parts of London and surrounding areas during Barack Obama's visit.
The US President and his wife Michelle arrive on Thursday night, just days after an unmanned aircraft is believed to have collided with a British Airways flight landing at Heathrow.
Detectives launched an investigation after the pilot of flight BA727 reported his aircraft being hit by a drone on Sunday afternoon with 132 passengers and five crew on board.
Flying restrictions will be in place at various locations until the Obamas depart on Sunday morning.
Under normal circumstances commercial operators may be allowed to fly a drone under 7kg within congested areas such as towns and cities as long as they remain at least 50 metres (164 feet) from all people and structures.
Amateur drone pilots are barred from flying within 150 metres (492 feet) of congested areas and within 50 metres (164 feet) of people, vehicles and structures.
But a Notice to Airmen has been issued by the UK's national air traffic service (Nats) and regulator the Civil Aviation Authority (CAA), stating that Transport Secretary Patrick McLoughlin decided flights must be restricted "as part of the overarching security plan" for the presidential visit.
Drones will be banned from flying between 9pm on Thursday and 11am on Sunday in and around London.
A large part of the capital will be affected, from Croydon in the south to Haringey in the north.
Restrictions are in place for the skies between Windsor and London on Friday - when the Obamas will join the Queen for lunch at Windsor Castle the day after her 90th birthday celebrations - and between Stansted airport and London on Thursday night and Sunday morning.
The regulations prohibit aircraft - including drones - from flying below 762 metres (2,500 feet) within the specified areas unless they are using Heathrow, Stansted or London City airports, London Heliport, RAF Northolt or are being operated by the emergency services.
Pilots of other aircraft wanting to fly in restricted areas must seek permission from the Metropolitan Police.
Similar rules have been put in place for previous significant events such as high-profile visits and major sporting fixtures.