President Trump has threatened to hit more than a dozen nations with steep import duties by next month. Mr. Trump initially posted two nearly identical letters on Monday, addressed to Japanese Prime Minister Shigeru Ishiba and South Korean President Lee Jae-myung,

President Donald Trump cranked up the pressure Monday on America’s trading partners, firing off letters to heads of several countries, informing them of their new tariff rate. But at the same time, Trump took some of the edge off by signing an executive action Monday to extend the date for all “reciprocal” tariffs,