Trump’s increased tariffs on steel and aluminium imports took effect today as prior exemptions, duty free quotas and product exclusions expired, and as his campaign to reorder global trade norms in favour of Washington gains momentum.

Canada is the biggest foreign supplier of steel and aluminium to the US.

Canada’s retaliation targets steel products worth C$12.6 billion and aluminium products worth C$3 billion as well as additional imported US goods worth C$14.2 billion for a total of C$29.8 billion.

Products affected by Canada’s counter-tariffs include computers, sports equipment and cast iron products, LeBlanc said at a news conference.

The escalation of the US-Canada trade war occurred as Prime Minister Justin Trudeau prepared to hand over power this week to his successor Mark Carney, who won the leadership race of the ruling Liberals on Sunday.

On Monday, Carney said he could not speak with Trump until he was sworn in as prime minister.

Trump again on social media said he wanted Canada “to become our cherished 51st state”.