There was an awful lot of talk - and no small controversy - about the how much it would cost to protect Donald Trump when he spends his time in New York rather than Washington.

This week, some sharp-eyed New Yorkers spotted military planes flying over Manhattan, close to Trump Tower, in what was apparently a training exercise to prepare for evacuating the President-elect in the case of an emergency.

NCB reported that the planes and helicopters seen flying last week were taking part in an exercise to locate a landing spot for a military chopper close to the Trump Tower, located at the bottom of Central Park. It said the operation involved two Blackhawk helicopters and a C-130 plane.

Retired Army Maj Mike Lyons, a military analyst, told the network that the mission may have also been looking at rooftops in the city that could help as possible evacuation routes.

“Police and law enforcement have got to be creative as terrorists could be in recognising that during 9/11 they weren’t able to evacuate anyone from the rooftop,” he said.

“The first thing they are likely looking at is a possibility from Trump Tower.”