The president has already threatened an additional 10% tariff on goods from countries aligning themselves with a bloc of nations that includes China and Russia.

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 that informed them of their new tariff rate.

Financial markets are on edge about higher import taxes, but White House officials say they anticipate “a lot of deals very quickly.”