United Airlines Holdings Inc said on Monday it was adding three flights to destinations in Europe from July as countries begin reopening to vaccinated travelers.

The airline said in a statement that it would add direct flights to Croatia, Greece and Iceland, the bookings for which have already begun.

Customers can upload their COVID-19 testing and vaccine documents to get them certified ahead of the check-in, the carrier said

United, which is slated to report earnings on Monday after markets close, said earlier this month that it expects a 66% drop in first-quarter revenue. 

(Reporting by Shreyasee Raj in Bengaluru; Editing by Aditya Soni) ((Shreyasee.Raj@thomsonreuters.com;))