Delta Airlines pre-flight cleaning crew members use electrostatic disinfection devices to clean an aircraft at JFK International Airport in New York, US, August 6, 2020. Picture August 6, 2020. (Photo: Agencies)

WASHINGTON - A group representing major US airlines on Thursday backed President-elect Joe Biden's plan to mandate facial coverings for all air passengers, but asked him to lift it once the coronavirus pandemic ends and give them flexibilities in enforcing it.

Airlines for America, which represents American Airlines Co, Delta Air Lines, United Airlines and others, asked Biden in a letter seen by Reuters to "allow air carriers to maintain their existing policies and practices which are aimed at de-escalating conflict in-flight and allowing the aircraft to continue while providing a consequential enforcement backstop on the ground."