President Donald Trump attacked GM and its CEO Mary Barra in a Fox interview on Thursday, saying "she’s making a big mistake" in not diverging from plans to close five plants and eliminate as many as 15,000 jobs.

"To tell me a couple weeks before Christmas that she's going to close in Ohio and Michigan — not acceptable to me," Trump said. "And she's either going to open fast or somebody else is going in."

Without specifying any plans for how he would carry out the threat, he continued, "General Motors is not going to be treated well."

But Trump's other comments during the interview with Fox News host Harris Faulkner left it unclear how concerned he truly is about GM's moves, particularly the shutdown of an Ohio plant.

“It doesn’t really matter,” the president said.

The 1,600 jobs that will be lost at the Lordstown Assembly Plant near Cleveland will be replaced “like in two minutes,” he said.

The president continued to attack GM and, in particular, Barra — the industry’s first female CEO — contending what she did in ordering the plant closures and elimination of 15 percent of GM’s white-collar workforce “was nasty.”

Trump has been a harsh critic of the auto industry since launching his campaign for the White House, reserving some of his fiercest comments for Detroit-based automakers. He repeatedly called out Ford Motor Co. for plans to move production of small cars to Mexico, even though it planned to replace them with more popular SUVs and pickups that the automaker said would create more jobs.

GM has also taken heat on a number of occasions, but the attacks amped up last month when the company indicated it would cut its white-collar workforce and end production of six slow-selling passenger car models. That move would mean the closure of three assembly plants in Michigan, Ontario and Ohio, as well as two powertrain factories in Michigan and Maryland.

"Very disappointed with General Motors and their CEO, Mary Barra, for closing plants in Ohio, Michigan and Maryland. Nothing being closed in Mexico & China. The U.S. saved General Motors, and this is the THANKS we get," he wrote in one of his first tweets on the closings.

Soon after, he told The Wall Street Journal, "They better damn well open a new plant (in Ohio) very quickly."

The focus on Ohio is not surprising. It's a swing state that backed candidate Trump in 2016 and generally stayed in the red column during the midterms. But political analysts believe it could go blue in 2020, especially if the president doesn’t deliver on his rhetoric, including the promise of bringing automotive jobs back to the state.

General Motors' Lordstown plant in Lordstown, Ohio, on Nov. 27, 2018. GM is cutting thousands of jobs in a restructuring, including 1,600 jobs at the Lordstown plant. John Minchillo / AP file

Trump contacted Barra after the jobs announcement, and she has since faced several days of contentious meetings on Capitol Hill. So far, however, the automaker has dug in, insisting it won’t back down on its planned cuts.

That puts the president in a bind if he can’t deliver. The Fox News interview appears to suggest he plans to continue projecting a tough face on the subject even as he prepares Ohio and its autoworkers for the likelihood that the Lordstown shutdown is irreversible.

But he then appeared to downplay the plant shutdown, saying: “It doesn’t really matter because Ohio is under my leadership from a national standpoint. Ohio’s going to replace those jobs like in two minutes. But I don’t that General Motors does that. And they’re going down to Mexico to make cars.”

That’s despite the new USMCA trade deal Trump took credit for negotiating to replace the North American Free Trade Agreement. The new deal, he said, “really makes it very uncomfortable for people to go out of the country, and it will be very uncomfortable for them. I think she’s making a big mistake.”

Trump concluded his comments on GM by insisting the automaker’s ongoing shift to battery-electric vehicles “is a mistake,” and that it is “not going to work.”