President Donald Trump cranked up the pressure on two of America’s key trading partners, Japan and South Korea, firing off letters Monday to the heads of their countries, informing them of their new tariff rate.

President Donald Trump announced tariffs of 25% on goods from Japan and South Korea beginning on Aug. 1, as he moved to impose unilateral rates on countries that have not yet secured trade deals with his administration.

President Donald Trump plans to impose a 25 percent tariff on goods imported from South Korea and Japan. The levy will go into effect on August 1st, which is when the Trump administration will begin enforcing sweeping tariffs on a wider swath of countries that fail to reach a trade agreement with the US.