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.

Trump posted on social media that the tariffs were necessary “to protect Americans,” pressing the three nations to do more to curb the manufacture and export of illicit fentanyl and for Canada and

President Donald Trump on Saturday signed an order to impose stiff tariffs on imports from Mexico, Canada and China — fulfilling one of his post-campaign commitments to voters that threatened to spark higher inflation and disrupt businesses across North America as the countries vowed harsh measures in response.