UAW President Shawn Fain threatened late Monday to expand the union's historic strike against the Detroit Three by noon Friday if "substantial progress" isn't made toward a "fair agreement," according to a union news release.

"We’re going to keep hitting the company where we need to, when we need to. And we’re not going to keep waiting around forever while they drag this out," Fain said in the release. "I have been clear with the Big Three every step of the way. And I’m going to be crystal clear again right now. If we don’t make serious progress by noon on Friday, September 22nd, more locals will be called on to Stand Up and join the strike."

The union's strategy, which it calls the Stand-Up Strike, involves targeted strikes at select auto plants designed to keep company officials guessing. So far, the UAW has ordered strikes at three plants in Michigan, Ohio and Missouri in what the union has called the first wave of shutdowns.

Talks between the UAW and each of the automakers resumed over the last few days following the start of the strike, with workers picketing at the three plants following the expiration of contracts Thursday night.

It remained unclear Monday night how long it will be before the union and automakers are ready to reach a deal.

The UAW held formal meetings with Ford Motor Co. on Saturday, General Motors on Sunday and Stellantis, which owns Jeep, Ram, Chrysler Dodge and Fiat, on Monday, although talks below the leadership level are said to be generally ongoing.

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The sides offered few details in most cases of the weekend meetings, although they did provide a few comments.

The UAW provided a bit more about its Ford talks than it did on the other automakers, saying on Saturday that "we had reasonably productive conversations with Ford today." A Ford spokeswoman has been asked for comment.

As for GM, both sides would confirm only that a meeting had taken place. GM spokesman David Barnas said negotiations continued Monday.

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The union had not provided a statement on its Stellantis meeting by Monday evening. The company, however, did weigh in:

“The discussion was constructive and focused on where we can find common ground to reach an agreement that provides a bridge to the future by enabling the company to meet the challenges of electrification. Together with the UAW, we have the opportunity to establish a framework in this contract that will allow the company to be competitive during this historic transformation and bring our workforce along on this journey,” according to a company statement provided by spokeswoman Jodi Tinson.

Stellantis also said it wants to continue discussing a solution for its idled Belvidere Assembly Plant in Illinois. The fate of that plant, which formerly produced the Jeep Cherokee SUV, has been a source of friction between the two sides. That was on display this weekend after Mark Stewart, chief operating officer for the automaker, said the company had proposed a “solution,” declining to provide details to the media, but that the offer had been contingent on reaching a deal last week by the expiration of the contract.

That prompted Fain to accuse the company of viewing workers as a bargaining chip and the company to respond that “the UAW leadership ignored Belvidere in favor of a strike.”

The union was awaiting counter-proposals from the three companies.

Contact Eric D. Lawrence: [email protected]. Become a subscriber.