The U.S. Court of International Trade and others argue the authority to impose tariffs lies with Congress, rendering the tariffs imposed by President Donald Trump on April 2 illegal.

The legal confusion over tariffs has buffeted U.S. trading partners around the world, casting doubt on the durability of Trump’s favorite bargaining tool.

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,