(DETROIT) — A labor strike against the three largest motor vehicle manufacturers in the United States could expand if ongoing contract negotiations don’t move toward a deal by Friday.

United Auto Workers President Shawn Fain is expected to make an announcement at 10 a.m. ET. He had warned earlier this week that the deadline for “serious progress” to be made in the union’s talks with General Motors, Ford and Stellantis — often called the “big three” — is Friday at noon.

“That will mark more than a week since our first members walked out. And that will mark more than a week of the ‘big three’ failing to make progress in negotiations toward reaching a deal that does right by our members,” Fain said in a video message posted on social media on Monday evening. “Autoworkers have waited long enough to make things right at the ‘big three.’ We’re not waiting around, and we’re not messing around.”

The UAW, which represents nearly 150,000 American autoworkers, launched a strike against GM, Ford and Stellantis on Sept. 15. Almost 13,000 workers walked out of three auto plants in Michigan, Missouri and Ohio that day. The union is utilizing a “stand-up” strike method to target specific plants and add to the list if a deal isn’t reached.

The UAW held talks with Ford on Sept. 16, GM on Sept. 17 and Stellantis on Sept. 18, a union source told ABC News. The conversations with Ford were “reasonably productive,” the source said.

Sticking points in negotiations were wage increases and the length of the workweek. The union is demanding a 46% pay increase combined over the four-year duration of a new contract, as well as a 32-hour workweek at 40-hour pay. So far, all three of the Detroit-based companies have each put forward proposals that offered workers a 20% pay increase over the life of the agreement but preserved a 40-hour workweek.

After the unprecedented strike began, Ford laid off 600 workers who assemble cars at a plant in Michigan on Sept. 15. Workers in the paint department at a nearby plant are out on strike, leaving the assembly workers without adequate parts since the parts require paint before they can be put together into cars, a company spokesperson told ABC News.

President Joe Biden has deployed acting Labor Secretary Julie Su and White House senior adviser Gene Sperling to Detroit to offer their support for the parties in reaching an agreement.

Economists previously told ABC News that a strike could result in billions of dollars in losses, disruption to the supply chain and other financial consequences.

ABC News’ Meredith Deliso, Jolie Lash and Max Zahn contributed to this report.

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