Over 20 nations — from economic allies like Canada and Japan to developing economies such as Cambodia and Sri Lanka — have received letters from Donald Trump threatening steep tariffs by August 1.

US President Donald Trump has announced new tariffs against Canada from next month in a letter to Prime Minister Mark Carney. The EU is expecting to receive a similar letter on Friday.

Trump threatened to impose a 35 percent tariff on Canadian goods beginning Aug. 1 unless Canada decides to build or ...