WASHINGTON, Sept 21 (Reuters) - United Airlines said on Wednesday it is working to resume flights to Cuba this winter that it suspended in March 2020 because of the COVID-19 pandemic.

The Chicago-based U.S. airline said it has been working for months to relaunch service but faces hurdles. It asked the U.S. Transportation Department for a waiver for 30 additional days as it works to resume service. Other airlines including American Airlines and JetBlue Airways are adding more flights to Cuba. (Reporting by David Shepardson; Editing by Leslie Adler)