Canada and Mexico ordered retaliatory tariffs on American goods in response to sweeping tariffs imposed by President Donald Trump, and businesses and consumers in both countries questioned Sunday how the new trade war might affect them.

President Donald Trump's new tariff orders against Canada, Mexico and China all contain clauses suspending a duty-free exemption for low-value shipments below $800 that is widely seen as a loophole that has allowed shipments of fentanyl and its precursor chemicals into the United States.