The new trade agreement between Japan and the Trump administration could give cars made in that country an advantage over vehicles that come from Canada and Mexico.

President Trump’s agreement with Japan, which was announced on Tuesday, will impose a 15 percent tariff on cars, which is considerably lower than the 25 percent tax he placed on all imported vehicles in April.

On Wednesday, a group representing three of the largest U.S. automakers — General Motors, Ford Motor and Stellantis — said the deal could set those companies back. Those three automakers collectively make more than two million cars and trucks in Canada and Mexico, many of them with American-made engines, transmissions and other parts. Those vehicles will still be subject to 25 percent tariffs.

The three companies worry that Mr. Trump’s agreement with Japan will give automakers like Toyota Motor and Honda a big leg up unless the administration reaches similar deals with Canada and Mexico.

“American automakers still need to review the details of the U.S.-Japan agreement, but any deal that charges a lower tariff for Japanese imports with virtually no U.S. content than it does North American-built vehicles with high U.S. content is a bad deal for the U.S. industry and U.S. autoworkers,” Matt Blunt, president of the American Automotive Policy Council, said in a statement. The council represents G.M., Ford and Stellantis.

A group that represents the U.S. operations of several foreign automakers, known as Autos Drive America, said it was urging the Trump administration to reach similar agreements with Canada, Mexico, South Korea and the European Union.