American Airlines has sent out furlough or place on temporary leave notices out to about 13,000 employees, just as federal coronavirus relief aid is set to expire.

Among those getting notices are 1,800 pilots, 4,200 flight attendants, 1,400 maintenance workers, 3,100 in fleet services, 1,200 passenger service staffers, 100 dispatch employees and 40 cleaning crew members, the carrier said on Thursday.

“We are nearly five weeks into 2021, and unfortunately, we find ourselves in a situation similar to much of 2020,” American said in a filing with federal regulators.

“We fully believed that we would be looking at a summer schedule where we’d fly all of our airplanes and need the full strength of our team. Regrettably, that is no longer the case,” it added.

American said the national distribution of coronavirus disease 2019 vaccines is moving at a much slower pace than expected and new restrictions on international travel, which require customers to provide negative coronavirus tests, have “dampened demand.”

“We will fly at least 45 percent less in the first quarter [of 2021] compared to what we flew for the same period in 2019, and based on current demand outlook, we will not fly all of our aircraft this summer as planned,” American added.

“Consequently, like last fall, we will have more team members than the schedule requires after federal payroll support expires April 1,” it added.

The Allied Pilots Association, the carrier’s pilots union, said it hopes for an extension of the federally funded Payroll Support Program, but placed some blame for the furloughs on American’s past fiscal decisions.

“Management’s unilateral actions over the years, along with their treatment of our airline’s balance sheet, have placed American in a more precarious situation than our competitors,” the union said in a statement.

“Collaboration with APA will be key if management hopes to successfully navigate these turbulent times.”

United Airlines recently said it may have to lay off as many as 14,000 of its workers.