America’s trading partners have reacted with fury after US President Donald Trump announced plans for long-promised tariffs of up to 25 per cent on automotive imports.

“What we’re going to be doing is a 25 per cent tariff for all cars that are not made in the United States,” Trump said at an event in the Oval Office on Thursday (Australian time).

“We start off with a 2.5 per cent base, which is what we’re at, and go to 25 per cent.”

The move widens the global trade war Trump started upon regaining the White House this year. Car industry experts expect it will drive up prices and stymie production.

European Commission President Ursula von der Leyen described the move as “bad for businesses, worse for consumers”, while Canadian Prime Minister Mark Carney labeled it a “direct attack” on Canadian workers.

“We will defend our workers, we will defend our companies, we will defend our country, and we will defend it together,” Carney said.

However, United Auto Workers union – a long-standing critic of free trade agreements it says have destroyed American jobs – lauded the move.

“These tariffs are a major step in the right direction for auto workers and blue-collar communities across the country, and it is now on the automakers, from the Big Three to Volkswagen and beyond, to bring back good union jobs to the US,” UAW President Shawn Fain said.

Trump has long promised higher duties on imported cars. The timing of Thursday’s announcement suggests that they will coincide with his April 2 plans for reciprocal tariffs aimed at countries responsible for the bulk of the US trade deficit.

Trump sees tariffs as a tool to raise revenue to offset his promised tax cuts and to revive a long-declining US industrial base. He has promised for weeks to announce the levies, and possibly some additional sectoral tariffs, on April 2 – a day he has dubbed “liberation day”.

Shares of US-listed car makers fell on news of the decision, amid concerns tariffs will send shock waves through a global auto industry already reeling from uncertainty caused by Trump’s rapid-fire tariff threats and occasional reversals.

The US stock market also closed lower on worries over tariffs, which have dogged investors for much of the past month. The benchmark S&P 500 Index fell 1.1 per cent ahead his announcement, and is down more than 4 per cent so far in March for its worst monthly performance in nearly a year.

Tariffs could drive costs of cars higher for US consumers by thousands of dollars, hitting new vehicle sales and resulting in job losses. The US car industry relies heavily on imported parts, according to the Centre for Automotive Research.

The country imported $US474 billion ($A751 billion) worth of vehicle products in 2024, including passenger cars worth $US220 billion.

Mexico, Japan, South Korea, Canada and Germany were the biggest suppliers.

On Wednesday, car services provider Cox Automotive forecast that if there were no tariff carve outs for the auto industry on imports from Mexico and Canada, $US3000 would be added to the cost of a US-made vehicle and $US6000 on a vehicle made in Canada or Mexico.

Since taking office on January 20, Trump has announced and delayed tariffs on Canada and Mexico for what he alleges is their role in allowing the opioid fentanyl into the US; set import taxes on goods from China for the same reason; launched hefty duties on imports of steel and aluminium; and has repeatedly touted his plans to announce global reciprocal tariffs on April 2.

-with AP