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.

The Trump administration touts tariffs as part of a wider set of "America First economic policies," which have "sparked trillions of dollars in new investment in U.S. manufacturing, technology, and infrastructure," according to the White House's website.

President Donald Trump announced a new trade deal with South Korea, which calls for 15% tariffs on goods from there.