President Donald Trump has signed an order to impose stiff tariffs on imports from Mexico, Canada and China, drawing swift retaliation from the U.S.’s North American neighbors in an emerging trade war.

President Donald Trump took action Saturday to impose new tariffs on Canada, Mexico and China, which could have a sweeping impact on the American economy. The additional tariffs on Canadian and Mexican goods will be 25 percent,

The president had promised action, though his team had been in negotiations over how to potentially dial back tariffs.