Washington DC - President Donald Trump on Monday imposed new 50% tariffs on many Canadian goods, claiming "discriminatory treatment" by Ottawa against US alcohol, automobile, and dairy products.

The tariffs will take effect in 30 days and cover a collection of Canadian exports, including wine, hockey sticks, and cement, the White House said.

Trump, who saw many of his tariffs struck down by the Supreme Court this year, tapped Section 338 of the 1930 Tariff Act – an untested legal provision.

The latest duties will not apply to energy, potash, and goods already impacted by sector-specific tariffs. They will, however, hit products covered under the US-Mexico-Canada Agreement (USMCA).

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This further rattles the future of the USMCA, which the Trump administration refused to extend on July 1.

"President Trump is offsetting the burden and disadvantage on US commerce… and is leveling the playing field for crucial American exports – cars, alcohol, and dairy," read a fact sheet released by the White House.

Canadian Prime Minister Mark Carney said in response that Ottawa stands ready to "intensify" talks with the US, and has made proposals to resolve disputes and modernize the USMCA.

"This is the latest in a series of unilateral US trade actions that began with the US imposing a series of tariffs in direct violation of the [USMCA]," he added. "Canada, as is its right, has merely matched those measures."

While Trump has slapped duties on US trading partners since reentering office last year, the orders often exempted goods entering under the USMCA.

His latest actions could further strain ties with the second largest US trade partner, coming just days after he threatened Canada with increased tariffs over wildfire smoke that descended into the US.

The tariff announcement aims to "hold Canada accountable for its retaliation and discrimination," said US Trade Representative Jamieson Greer.