WASHINGTON (AP) — President Donald Trump has told Congress he is canceling a pay raise that most civilian federal employees were due to receive in January, citing budgetary constraints.

Trump informed House and Senate leaders in a letter sent Thursday.

Trump says in the letter that locality pay increases would cost $25 billion, on top of a 2.1 percent across-the-board increase for most civilian government employees.

He cites the costs and says: “We must maintain efforts to put our Nation on a fiscally sustainable course, and Federal agency budgets cannot sustain such increases.” Trump says he’s determined that for 2019 “both across-the-board pay increases and locality pay increases will be set at zero.”

Under the law the 2.1 percent raise takes effect automatically unless the president and Congress act to change it. Congress is debating a proposal for a slightly lower 1.9 percent across the board raise to be included in a government funding bill that would require Trump’s signature to keep most government functions operating past September.

Unions representing the 2 million-member federal workforce urged Congress to pass the 1.9 percent pay raise.