Paris, France - The head of Canada's foreign investment promotion agency has said that Donald Trump's proposed tariffs on Canadian goods would serve no purpose and only hurt the US.

President-elect Trump has threatened to slap a 25% tariff on imports from Canada and Mexico, whom he accuses of flooding the US with illegal drugs and undocumented immigrants.

Canada's largest province, Ontario, has threatened to sever energy exports to the US in response to such a tariff regime.

"I think from a business perspective, no one will benefit from a tariff regime," said Lauren Broten, chief executive of Invest in Canada.

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"The establishment of tariffs would not only be problematic for Canada, it would be problematic for many US states," Broten told the AFP.

"I think the government of Canada and the US government will need to work through this."

In particular, Broten expressed concern for the US' energy and auto sectors, which are intricately intertwined with imported goods and services from Canada.

"A piece comes from here, it gets attached to something here, it comes back across," she said. "There's no car manufacturer in North America that wants to see seven tariffs on their vehicle parts as they cross the border."

Trump met with Canadian Prime Minister Justin Trudeau at Mar-a-Lago in November to discuss the proposed tariffs, which the Canadian leader said would be "devastating" for his country.

"One of the things that is really important to understand is that Donald Trump, when he makes statements like that, he plans on carrying them out. There's no question about it," Trudeau told reporters after the meeting.

"Our responsibility is to point out that in this way he would be actually not just be harming Canadians, who work so well with the United States; he'd actually be raising prices for American citizens as well and hurting American industry and businesses."