Trudeau, who is in Paris for a global AI (artificial intelligence) conference, was reacting to the news Monday that US President Donald Trump had instituted tariffs on all imports of the two products, including those from Canada. The tariffs take effect March 4.

“Speaking to travelling reporters just as the sun was rising in Paris, Trudeau said that the federal government will be working with U.S. administration in the lead-up to the tariffs coming into effect, to highlight their negative impact, but ‘if it comes to that, our response of course will be firm and clear.’”

As top exporter of steel and aluminium to the US, Canada sees new trade barriers as a threat to their economy.