President Donald Trump signed an executive order Thursday, slapping tariffs on most of America's trading partners set to take effect next week.

Crucial exporters to the US such as Taiwan, the world’s most important semiconductor exporter, will incur steep new levies. Trump also raised tariffs on Canada, an ally and major trading partner, to 35 per cent. India was hit with a rate of 25 per cent and Switzerland with 39 per cent.

It follows similar drops in markets in Europe and Asia after the US president said he was moving forward with tariff plans.