In a recent interview with CNBC, President Donald Trump threatened to place a 250 percent tariff on all pharmaceutical imports.

WASHINGTON—President Donald Trump was set to officially begin levying higher import taxes on dozens of countries on Thursday, just as the economic fallout of his monthslong tariff threats has begun to create visible damage for the US economy.

Despite the uncertainty, the White House is confident that the onset of his tariffs will provide clarity about the path for the world's largest economy. Now that companies understand the direction the U.