WASHINGTON (Reuters) - Major U.S. airlines and aviation unions on Thursday urged the Biden administration to pause approvals of additional flights between China and the United States, citing ongoing "anti-competitive policies of the Chinese government."

In February, the U.S. Transportation Department said Chinese passenger airlines could boost weekly round-trip U.S. flights to 50 starting on March 31, up from the current 35, about a third of pre-pandemic levels.

Airlines for America, which represents American Airlines ( AAL ), United Airlines, Delta Air Lines ( DAL ) and others, and unions in a letter the Transportation and State departments seen by Reuters cited the "advantage Chinese airlines receive by continuing to access Russian airspace, while U.S. carriers stopped flying through Russian airspace at the start of Russia's invasion of Ukraine in March 2022."