By Jeff Mason and Leika Kihara WASHINGTON/TOKYO (Reuters) -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.

President Donald Trump on July 7 threatened to impose 25 percent tariffs on Japan and South Korea, and levies as high as 40 percent on 12 other countries, if they did not reach a deal by August 1.

Asian countries including Japan and South Korea said they’ll keep pushing for a better deal for their exports to the US after President Donald Trump shifted his tariff deadline to Aug. 1 and tweaked the rates he’s set for many economies.