The U.S. Constitution gives the power to impose taxes — including tariffs — to Congress. But lawmakers have gradually relinquished power over trade policy to the White House. And Trump has made the most of the power vacuum, raising the average U.S. tariff to more than 18%, highest since 1934, according to the Budget Lab at Yale University.

The tariffs mark a new phase in what has been a complicated and at times chaotic push to reset the terms of global trade. Treasury Secretary Scott Bessent suggested on Tuesday that more deals could come together in the coming weeks, meaning the rates are still subject to change.

President Donald Trump has announced a flurry of trade activity ahead of Friday's official start of his new tariffs regime — executive actions including 50% tariffs on Brazil, a 15% tax on American imports from South Korea and an end to exemptions for imported goods worth less than $800.