The sweeping levies imposed on nearly every country mark a watershed moment in the president's effort to upend world trade.

U.S. trade partners such as Switzerland, Brazil and India were still scrambling to get a better deal on Thursday as President Donald Trump's higher tariff rates on imports from dozens of countries kicked in,

Olu Sonola, the head of U.S. economic research at Fitch Ratings, said the economy was just “starting to see” the effects of the tariffs that Mr. Trump announced in the spring, adding that with Mr. Trump’s newest duties now in place, Americans would “see that magnified” in coming months.