The move fulfills campaign promises but also sparked retaliatory moves that could signal an extended trade war with key trading partners.

Trump has long proposed raising tariffs—or taxes on imported goods that the businesses importing them pay the U.S. government—before the election, and said in November he’ll impose a 25% tariff rate on all imports from Mexico and Canada on the first day of his presidency and will impose an additional 10% tariff rate on all imports from China on top of other tariffs.