Canadian Prime Minister Mark Carney on Thursday said he would speak with US President Donald Trump in the coming days after the latter announced 25 per cent tariffs on auto imports.

Carney, who hasn't spoken with Trump since becoming Canada's new leader nearly two weeks ago, said the US president reached out on Wednesday night to schedule a call.

"We will be speaking soon, certainly in the course of the next day or two," Carney said.

He also said that Trump has to respect Canada's sovereignty.

"That's not much to ask, but apparently it's a lot for him," he said.

Trump has declared a trade war on Canada and continues to call for the United States' northern neighbour to become the 51st US state, a position that has infuriated Canadians.

"The old relationship we had with the United States, based on deepening integration of our economies and tight security and military cooperations, is over," Prime Minister Carney told reporters. "The time will come for a broad renegotiation of our security and trade relationship."

Carney was sworn in as Canada's new prime minister on March 14. It's unusual for a US president and Canadian prime minister to go so long without talking after a new leader takes office.

Carney, who replaced Justin Trudeau as Canada's leader and the head of the Liberal Party, is at the start of a five-week campaign after calling an early election for April 28.

The governing Liberals had appeared poised for a historic election defeat this year until Trump declared a trade war and challenged Canada's sovereignty. The crisis has created a surge in patriotism among Canadians, with many in the country feeling that Carney is the best person to lead Canada at the moment.

Trump has acknowledged himself that he has upended Canadian politics.

Carney has called the tariffs unjustified and left the election campaign to chair his special Cabinet committee on US relations in Ottawa.

Automobiles are Canada's second-largest export and the sector employs 125,000 Canadians directly and almost another 500,000 in related industries.

Trump previously had granted a one-month exemption on his stiff new tariffs on auto imports from Mexico and Canada for US automakers.

In the auto sector, parts can go back and forth across the Canada-US border several times before being fully assembled in Ontario or Michigan.

Trump previously placed 25 per cent tariffs on Canada's steel and aluminum and is threatening sweeping tariffs on all Canadian products -- as well as on all of America's trading partners -- on April 2.