Dhaka, March 4 -- US President Donald Trump's new 25 per cent tariffs on imports from Mexico and Canada took effect on Tuesday, along with a doubling of duties on Chinese goods to 20 per cent, launching new trade conflicts with the top three US trading partners.

The tariff actions, which could upend nearly $2.2 trillion in two-way annual US trade went live at 12:01 am EST (0501 GMT), hours after Trump declared that all three countries had failed to do enough to stem the flow of the deadly fentanyl opioid and its precursor chemicals into the US..

China responded immediately after the deadline, announcing additional tariffs of 10%-15% on certain US imports from March 10 and a series of new export restrictions for designated US entities, a...