U.S. stocks showed little change in the first trading since President Donald Trump announced 25% auto tariffs, escalating a global trade war and prompting forecasts of higher car prices.

The Dow Jones Industrial Average ticked down 150 points, or 0.35%, while the S&P 500 dropped 0.3%. The tech-heavy Nasdaq declined 0.25%.

The 25% tariffs will be applied to imported passenger vehicles, including cars, SUVs, minivans, cargo vans and light trucks, according to a White House fact sheet released after Trump's Oval Office remarks. The tariffs will take effect on April 3.

The tariffs will also be applied to key imported auto parts, including engines, powertrain parts and electrical components.

The auto tariffs are set to target a sector that employs more than a million U.S. workers and relies on a supply chain intricately intertwined with Mexico and Canada.

Canadian Prime Minister Mark Carney on Wednesday called the measure "a direct attack on our workers." The Canadian government plans to review its trade options, Carney said.

This is a developing story. Please check back for updates.