Trump’s promise to impose 30% tariffs on imports from Mexico and 35% on imports from Canada beginning tomorrow could hammer up to three-fourths of their U.S. imports.

U.S. President Donald Trump on Thursday signed an executive order increasing tariffs on Canadian goods to 35% from 25% on all products not covered by the U.S.-Mexico-Canada trade agreement, the White House said.

Trump has justified tariffs on goods from Canada, the top U.S. export market, by accusing it of failing to stop the cross-border flow of fentanyl, even though U.S. government data shows Canada accounts for only 1% of the fentanyl that enters the United States.