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

President Donald Trump signed an executive order Saturday imposing a 25% tariff on imports from Mexico and Canada and 10% on imported Chinese goods, according to multiple reports, reflecting his campaign promises to implement high tariffs,

The 25 percent tariffs on imported steel and aluminum are the latest salvo in his ongoing effort to overhaul the U.S. trading relationship with the rest of the world.