The carrier will launch a daily flight from Washington Dulles on May 23, running it until October 4. The Boeing 757 service will join United’s year-round New York Newark route from the Scottish capital and its summer-only Chicago flight.

The flight from Edinburgh will leave at 12.40, arriving at 15.40 and taking eight hours. The inbound service will leave at 22.10, arriving at 10.25 and taking seven hours 15 minutes.

The carrier has also revealed that it will extend the operating season of its summer-only Dublin-Chicago service. This will now run from April 9 2018 until October 26. United will also operate to Iceland for the first time next summer, with a daily flight from Newark.

"As we continue growing our global route network, we are offering more choice and convenience to travel to our U.S. hubs and beyond, something our customers have told us they want,” said Marcel Fuchs, United’s vice president Atlantic and Pacific sales.

He added: “The new seasonal summer flights offer customers even more opportunities to plan summer travel to the U.S. and connect onwards to more than 100 cities across North America."