The cheap Canadian oil America craves is becoming a key bargaining chip in President Trump’s threatened trade war.

Trump said in an Oval Office signing ceremony on Monday that his administration will impose a 25% tax on goods from Canada and Mexico that may come as soon as February 1 – a move that could raise prices for American consumers.

The president said he planned to put tariffs on America’s neighbors on Feb. 1, as he signed an executive order mandating a sweeping review of U.S. trade policy.