Southeast Asia's biggest economies prepared on Tuesday to step up trade negotiations with Washington after it hit them with steep tariffs, despite a last-ditch flurry of offers to boost imports and slash levies on U.

Japan, South Korea, Malaysia and Kazakhstan will face 25% import duties starting Aug. 1, while goods from Laos and Myanmar will face a 40% tariff.

So far, semiconductors are exempt from tariffs but Trump has threatened levies on them several times, and that uncertainty is making it near impossible for businesses to plan for the future. Also last week Bloomberg reported the White House is planning to further tighten controls over artificial intelligence (AI) chips by restricting shipments to Malaysia and Thailand to crack down on suspected smuggling of the technology to China.