Although COVID-19 cases in the U.S. have fallen sharply in the last two months and restrictions are being lifted across the country, the Centers for Disease Control and Prevention earlier this month extended its mass transit mask mandate by 30 days, until mid-April, and masking guidelines for airlines remain in place.

"Now is the time for the administration to sunset federal transportation travel restrictions – including the international predeparture testing requirement and the federal mask mandate – that are no longer aligned with the realities of the current epidemiological environment," the CEOs of 10 U.S.-based passenger and cargo airlines, including Delta, American and United, wrote in a letter to President Biden.