United Auto Workers President Shawn Fain on Monday said the White House will have no role in brokering an agreement to end the autoworkers’ strike as the walkout enters its fourth day with no resolution in sight.

“No, not at all,” Fain said when asked on MSNBC’s “Morning Joe” whether the White House could help the union and General Motors, Ford and Stellantis reach a deal.

“This battle is not about the president,” Fain said. “It’s not about the former president or any other person prior to that. This battle is about the workers standing up for economic and social justice and getting their fair share because they’re fed up with going backwards.”

Fain’s comments come after President Joe Biden said on Friday that he would send acting Labor Secretary Julie Su and White House senior advisor Gene Sperling to Detroit to help mediate the negotiations.

Treasury Secretary Janet Yellen told CNBC in an interview Monday that the White House wants a “win-win” deal. “The two sides need to narrow their disagreements and to work for a contract that’s good for the workers and for the industry as well,” Yellen said.

The strike has entered its fourth day with no resolution in sight. Nearly 13,000 UAW members are on strike at three key plants in Michigan, Missouri and Ohio.

Biden, who’s up for reelection next year, often touts his blue-collar roots and has sought to closely associate himself with the labor movement, but the strikes will test those credentials if the dispute is left unresolved and triggers broader economic disruption. Former President Donald Trump is also courting support from UAW members, while attacking the union’s leaders, as he pursues another term in the White House.

Biden largely sided with the striking workers in his brief address Friday, calling on the automakers to share the record profits they have made in recent years.

“Those record profits have not been shared fairly, in my view, with the workers,” the president said.

The autoworkers are demanding a 40% hourly wage increase, a 32-hour workweek, elimination of compensation tiers, a return to traditional pensions, the restoration of cost-of-living adjustments as well as better vacation and family leave benefits among other items.

“We have been very clear from the onset that we want to end tiers,” Fain told MSNBC. “You have workers on the line doing the same job for severely different rates of pay and there’s no excuse for that.”

The UAW president said the union’s members are prepared to escalate: “If the companies don’t respond to the members’ demands then we have to do what we have to do.”

The automakers have said the union’s demands would cripple the companies and put them at a disadvantage compared non-unionized car manufacturers. Ford CEO Jim Farley said in an interview with CNBC on Thursday that the automaker would have gone bankrupt under the UAW’s current demands.

Ford on Friday temporarily laid off 600 workers who are not striking at its assembly plant in Wayne, Michigan. GM has said its assembly plant in Fairfax, Missouri should shut down as soon as this week, impacting 2,000 workers.

Trump on Friday accused the UAW leadership of failing its members and claimed Biden administration’s efforts to transition to electric cars would result in manufacturing jobs shifting to China.

“The autoworkers are being sold down the river by their leadership, and their leadership should endorse Trump,” Trump, who is the frontrunner for the 2024 Republican nomination, told NBC News in an interview.