Sri Lanka, March 4 -- U.S. President Donald Trump's new 25% tariffs on imports from Mexico and Canada took effect on Tuesday, alongside a doubling of duties on Chinese goods to 20%, heightening trade tensions with the top three U.S. trading partners. The tariff actions, which could disrupt nearly $2.2 trillion in two-way annual U.S. trade, were enacted at 12:01 a.m. EST (0501 GMT), just hours after Trump declared that all three countries had not done enough to curb the flow of fentanyl and its precursor chemicals into the U.S.

Canada and Mexico, long accustomed to virtually tariff-free trade with the U.S., quickly vowed retaliation. Canadian Prime Minister Justin Trudeau announced that Ottawa would impose 25% tariffs on C$30 billion ($20...