President Trump on Monday said the U.S will impose 25% tariffs on goods from South Korea and Japan by August 1, while also threatening to hit five other nations with import duties of up to 40% by next month.

S tocks closed down significantly on Monday after President Donald Trump announced steep tariffs on seven countries and threatened to impose new levies on others. The Dow Jones Industrial Average closed down 422 points, or 0.9%, while the S&P 500 dropped 0.7%. The tech-heavy Nasdaq declined 0.9%.

President Donald Trump said he’ll impose tariffs of 25% on goods from Japan and South Korea beginning Aug. 1, giving the two export powers a narrow three-week window to open their markets to American products and manufacture more in the US to avoid his unilateral levies.