President Donald Trump has justified tariffs on Canadian imports by citing a flood of smuggled fentanyl. But nearly all of the powerful opioid is smuggled from Mexico.

U.S. tariffs on Canada have put experts at odds over how appropriate the action was, particularly given the unaddressed demand side of the fentanyl epidemic.

US President Donald Trump has said his tariffs on Canadian goods are necessary to force action on the migrants and drugs entering the United States through its northern border. He has also described billions of dollars in daily cross-border trade as a US subsidy and claimed Canada would not be "viable as a country" without it.