President Trump on Monday said the U.S will impose 25% tariffs on goods from South Korea and Japan by Aug. 1, while also threatening to hit a dozen other nations with steep import duties by next month.

President Donald Trump sent letters to the leaders of five more countries Wednesday, adding to the growing list of US trading partners for whom he has set new tariff rates.

President Trump has announced a new round of tariffs for six countries that include the Philippines, Iraq and Libya. NBC News' Brain Cheung reports on the announcement and the coming tariff negotiation deadline the Trump administration has put in place.