The White House said the president’s order includes a mechanism to escalate the rates if the countries retaliate, as they have threatened.

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.

Ties between the United States and Mexico have deepened over 30 years of free trade, creating both benefits and irritants.