President Trump slammed General Motors Tuesday after the automobile manufacturer announced their plans to reduce 15% of its American workforce; saying his administration would consider “cutting all subsidies” to the carmaker.

“Very disappointed with General Motors and their CEO, Mary Barra, for closing plants in Ohio, Michigan and Maryland. Nothing being closed in Mexico & China. The U.S. saved General Motors, and this is the THANKS we get! We are now looking at cutting all @GM subsidies, including electric cars. General Motors made a big China bet years ago when they built plants there (and in Mexico) – don’t think that bet is going to pay off. I am here to protect America’s Workers!” Trump tweeted.

….for electric cars. General Motors made a big China bet years ago when they built plants there (and in Mexico) – don’t think that bet is going to pay off. I am here to protect America’s Workers! — Donald J. Trump (@realDonaldTrump) November 27, 2018

News of the President’s threat caused GM’s shares to plunge more than 3.5% Tuesday, in what will likely be the company’s worst day in over a month.