Ford President and CEO Mark Fields addresses the Flat Rock Assembly Tuesday, Jan. 3, 2017, in Flat Rock, Mich. Ford is canceling plans to build a new $1.6 billion factory in Mexico and will invest $700 million in a Michigan plant to build new electric and autonomous vehicles. The factory will get 700 new jobs. (AP Photo/Carlos Osorio)
Ford President and CEO Mark Fields addresses the Flat Rock Assembly Tuesday, Jan. 3, 2017, in Flat Rock, Mich. Ford is canceling plans to build a new $1.6 billion factory in Mexico and will invest $700 million in a Michigan plant to build new electric and autonomous vehicles. The factory will get 700 new jobs. (AP Photo/Carlos Osorio) Credit: Carlos Osorio

Flat Rock, Mich. — The auto industry’s relationship with President-elect Donald Trump took a dramatic turn on Tuesday as Ford Motor Co. decided to shift investment dollars targeted for Mexico to the U.S., while Trump threatened General Motors with a tax on some imported small cars.

Ford is canceling plans to build a new $1.6 billion factory in San Luis Potosi, Mexico, and will instead invest some of that money in a U.S. factory that will build new electric and autonomous vehicles.

Ford said last spring it would move production of the Ford Focus small car to the new plant from Michigan. Trump repeatedly criticized the plan, and Ford was among the companies he threatened to hit with a 35 percent tariff on products made in Mexico and exported to the U.S.

Trump added General Motors to that group Tuesday, saying in a tweet that the Cruze small cars GM makes in Mexico and sends to U.S. dealers could face “a big border tax!”

Ford CEO Mark Fields said on Tuesday that market forces dictated Ford’s decision not to build the San Luis Potosi plant. Low gas prices and low interest rates have been hammering small-car sales. U.S. sales of the Focus were down 17 percent through November; by contrast, sales of Ford’s biggest SUV, the Expedition, were up 46 percent.

Ford will still move production of the Focus to Mexico, but it will go to an existing plant in Hermosillo that makes midsize cars.

The Wayne, Mich., plant that currently makes the Focus will get two new products next year, preserving jobs at the facility.

Fields said Ford will invest $700 million in the Flat Rock plant to make hybrid, electric and autonomous vehicles. It will also hire around 700 workers starting in 2018. In announcing the Michigan expansion, Fields noted Trump’s promise to make the U.S. more competitive by lowering taxes and easing regulations.

“This is a vote of confidence for President-elect Trump and some of the policies he may be pursuing,” Fields said at the company’s plant in Flat Rock.