President Trump said the U.S. will impose steep levies on imports from 14 countries starting next month, heightening pressure on trading partners.

The country’s new president, in office for a little over a month, had just dispatched his senior deputies to Washington to try to work out a trade deal.

Powerhouse Asian economies Japan and South Korea said on Tuesday they would try to negotiate with the U.S. to soften the impact of sharply higher tariffs that President Donald Trump now plans to impose from the start of August.