President Donald Trump has taken executive action to impose or threaten new tariffs on imports from Canada, Mexico and China. The moves fulfill certain campaign promises but also have roiled stock markets and supply chains,

The moves fulfill certain campaign promises but also have roiled stock markets and supply chains, while straining relations with the country’s North American neighbors.

Some lawmakers in the U.S. Congress have expressed dismay at President Donald Trump's threat to slap new tariffs on Canada, China and Mexico, but they have limited power to stop him.