Major Chinese airlines on Tuesday urged the administration of U.S. President Donald Trump to abandon a plan to bar them from flying over Russia on U.S. flights, saying it would boost flight times, raise air fares and could disrupt some routes.

Last week, the U.S. Transportation Department proposed banning Chinese airlines from flying over Russia on routes to and from the United States, saying the reduced flight time puts American carriers at a disadvantage.

China Eastern, one of six Chinese airlines that sent letters, said in a filing with USDOT that the move could extend the flight time on some of its most important routes by two to three hours, significantly increase risks of missed connections and boost fuel consumption.