Washington (United States) (AFP) - US President Donald Trump vowed Monday to double tariffs on Canadian vehicles beginning next year, as the historically friendly neighbors spiral into a trade war.

Trump’s threat comes after the North American allies failed Friday to reach a deal to avert new 50-percent US tariffs on select Canadian goods. The duties took effect Saturday, and Ottawa laid out plans for retaliation.

“On January First, 2027, Tariffs on all Cars, Trucks, both large and small, Automotive Parts, and Steel, will be increased to 50%,” Trump wrote Monday on his Truth Social platform.

The current US tariff impacting Canadian autos stands at 25 percent for non-US content, while imported steel to the United States generally faces a 50-percent duty. US automakers did not immediately comment on the matter.

After rejecting what he called a “bad deal,” Canadian Prime Minister Mark Carney announced retaliatory tariffs effective September 8.

These will target US steel and dairy industries, while also covering sectors like agricultural equipment, paper and electronics.

Carney said Monday that the goal of trade talks with Washington “has always been to get the best deal for Canadians, never a deal at any price or on any time frame.”

“We learned that, during the negotiations, the Americans wanted to destroy our major industries – including the automotive, steel, and aluminum sectors – through unfair negotiating terms. And that is one of the main reasons why we said no.”

He stressed that building domestically and diversifying trade abroad has been “plan A from the start.”

Over the weekend Carney added that, at the 11th hour, US negotiators also sought restrictions on Canadian trade deals with other countries.

US negotiators made unacceptable “threats” to the French language and “Quebec culture” too, he said, referring to eastern Canada’s French-speaking province.

At a separate event Monday, however, US Vice President JD Vance blamed Canada’s “unreasonable last-minute demands.”

The United States is by far Canada’s biggest trading partner, with Canadian exports to its neighbor representing 70 percent of its overall total.

Canada is the United States’ second biggest trading partner in goods this year, behind Mexico, government data showed.

- ‘We don’t need Canada’ -

Three in four Canadians support the Carney government’s decision to walk away from trade talks, according to polling released Sunday by the Angus Reid Institute.

However, the research group noted that two in five Canadians have some fear about their jobs.

Ontario Premier Doug Ford criticized Trump’s tariff threat on autos, saying he could “kiss my ass.”

Ford warned that an electricity surcharge was on the table. In an earlier phase of the dispute, Ontario imposed a 25-percent surcharge on electricity exports to three US states.

Trump lashed out at Ford online, warning of “far worse” consequences.

The White House had alleged “discriminatory treatment” by Canada against US alcohol, automobile and dairy products in rolling out the 50-percent tariffs.

Trump delayed their implementation by three days last week, but both sides failed to reach an agreement after talks went down to the wire.

The latest duties hit about 5.5 percent of Canadian goods entering the US, worth some $20 billion, impacting products like hockey sticks and cement.

Trump charged Monday that “Canada has been ripping off the United States of America for years,” adding “we don’t need Canada, they need us.”

US Trade Representative Jamieson Greer told The New York Times on Saturday that the Trump administration offered to eliminate a 10-percent tariff on softwood lumber, and reduce the 25-percent autos tariff.

Washington was also ready to cut steel tariffs from 50 percent to 25 percent for most Canadian steel, said Greer.

Besides the tariffs fight, Washington and Ottawa have to agree on revisions to the US-Mexico-Canada free trade agreement (USMCA) which Trump has declined to renew in its current form.

Trump has also repeatedly antagonized Canadians with his threats to make Canada a US state and calling Carney and his predecessor Justin Trudeau “governor” – as if they were US politicians, not prime ministers of an other country.