U.S. President Donald Trump on Thursday said his proposed 25% tariffs on Mexican and Canadian goods will take effect March 4 along with an extra 10% duty on Chinese imports because deadly drugs are still pouring into the U.

Trump's new tariff threat are of fresh tariffs which come in addition to the previous 10 per cent one levied on February 4.

US President Donald Trump threatened to double existing tariffs on China to 20% from next week, piling further pressure on the country’s beleaguered economy. Chinese stocks tanked after Beijing vowed to respond with “all necessary measures” against Trump’s plan.