U.S. President Donald Trump's tariff decisions since he took office on January 20 have shocked financial markets and sent a wave of uncertainty through the global economy. Here is a timeline of the major developments: February 1 - Trump imposes 25% tariffs on Mexican and most Canadian imports and 10% on goods from China,

The president revived his discredited claims about fentanyl entering the U.S. from Canada to justify his latest proposed rate of 35 percent.