Layoffs of federal workers have begun amid the ongoing U.S. government shutdown, Trump administration budget chief Russell Vought said in a social media post on Friday.

“The RIFs have begun,” Vought wrote on X, using the acronym for “Reductions in Force.”

The Office of Management and Budget, which Vought leads, confirmed that “RIFs have begun and are substantial.”

No other details of the layoffs were immediately released.

The announcement comes four days after National Economic Council Director Kevin Hassett warned in a CNBC interview that President Donald Trump could “start taking sharp measures” if the shutdown continued due to the lack of a stopgap funding deal approved by Congress.