AP PHOTO UAW members including Scott Kralovic, wearing a mask, work the picket line during a strike Tuesday, at the Stellantis Toledo Assembly Complex where Jeeps are made in Toledo, Ohio.

The United Auto Workers union is stepping up pressure on Detroit’s Big Three by threatening to expand its strike unless it sees major progress in contract negotiations by Friday.

In a video statement late Monday, UAW President Shawn Fain said workers at more factories will join those who are now in the fifth day of a strike at three plants.

“We’re not going to keep waiting around forever while they drag this out … and we’re not messing around,” Fain said in announcing the noon Eastern time Friday deadline for escalating the strike unless there is “serious progress” in the talks. The union plans to disclose the locations of new strikes during an online presentation to members Friday morning.

Ford, General Motors and Stellantis said they want to settle the strike, and they held back from directly criticizing the escalation threat.

Mark Stewart, the North American chief operating officer of Stellantis, the successor to Fiat Chrysler, said the company is still looking for common ground with the UAW.

“I hope that we’re able to do that by Friday,” Stewart said on CNBC.

GM said in a statement, “We’re continuing to bargain in good faith with the union to reach an agreement as quickly as possible for the benefit of our team members, customers, suppliers and communities across the U.S.”

A Ford spokeswoman said Tuesday that negotiations were continuing, but provided no additional details.

In Washington, the Biden administration reversed a plan to send acting Labor Secretary Julie Su and senior adviser Gene Sperling to Detroit this week to meet with both sides, according to a White House official. Last week, President Joe Biden publicly backed the UAW and said the officials could play a positive role.

The White House now believes that since negotiations are taking place, “it is most productive for Sperling and Su to continue their discussions from Washington and allow talks to move forward,” said the official, who spoke on condition of anonymity to discuss the private plans.

Fain had discounted the need for help from Washington, saying “This battle is not about the president,” and some Democrats opposed the White House involvement.

“I do not believe that the president himself should intervene as he did in the railroad strike in these talks. He should not be at that table,” said Rep. Debbie Dingell, whose congressional district includes part of southeast Michigan.

So far the strike is limited to about 13,000 workers at a Ford assembly plant in Wayne, Michigan, a GM factory in Wentzville, Missouri, and a Stellantis plant in Toledo, Ohio.

However, layoffs are starting to occur at other locations as the strike crimps the industry’s supply chain.

In Toledo, 12 different shops that supply the Jeep plant where UAW is striking have laid off more than 1,600 workers, according to Bruce Baumhower, president of the union local in northeast Ohio. More than half will get state unemployment benefits, while workers at two companies located inside the Jeep plant have been approved for payments from the union strike fund, “but they can’t picket because they’re not on strike,” he said.

GM warned Monday that the strike in Wentzville, near St. Louis, could force the company to idle an assembly plant in Kansas City early this week. On Tuesday, the company said that it expected to keep production going in Kansas City for at least one more day.