Mr. Ford’s remarks alluded to a period several decades ago when the U.A.W. won increasingly rich contracts that were later seen by many industry experts as having hobbled the three Michigan automakers in the face of competition from Japanese and European carmakers. Ford came to the brink of collapse, and G.M. and Chrysler — now part of Stellantis — had to seek bankruptcy protection after the 2008 financial crisis.

“Ford’s ability to invest in the future isn’t just a talking point,” Mr. Ford said. “It is the absolute lifeblood of our company. And if we lose it, we will lose to the competition. Many jobs will be lost.”

In a statement, the U.A.W. president, Shawn Fain, said Mr. Ford should “stop playing games” and meet the union’s demands, or “we’ll close the Rouge for him.” Mr. Fain added that the U.A.W. was not fighting the company but “corporate greed.”

“If Ford wants to be the all-American auto company, they can pay all-American wages and benefits,” Mr. Fain said. “Workers at Tesla, Toyota, Honda and others are not the enemy — they’re the U.A.W. members of the future.”

Ford, G.M. and Stellantis have been negotiating new labor contracts with the U.A.W. since July. Over the past month, the union has called on workers at a few plants to go on strike. The action has idled three Ford plants, two G.M. factories and one Stellantis plant. Workers at 38 G.M. and Stellantis spare-parts warehouses are also on strike.