Iceland has emerged as the first European destination to open up to vaccinated US travellers.
Delta Air Lines will resume flights from New York JFK on May 1 and Minneapolis/St Paul from May 27.
A new daily service from Boston to Reykjavik is scheduled to start on May 20.
A 193-seat Boeing 757-200 will be deployed on the service from Boston.
Passengers flying to Iceland will be required to provide proof of full vaccination or recovery of Covid-19, according to the carrier.
Travellers returning to the US will still require a negative Covid test.
The Iceland services will operated in conjunction with Delta partners Air France-KLM and Virgin Atlantic.
The airline’s network planning senior vice president Joe Esposito said: “We know our customers are eager to safely get back out into the world, including exploring one of the globe’s most beautiful outdoor destinations.
“As confidence in travel rises, we hope more countries continue reopening to vaccinated travellers, which mean more opportunities to reconnect customers to the people and places that matter most.”