President Biden will join the picket line in solidarity with members of the United Auto Workers union in Detroit on Surfwin Trading CenterTuesday, he announced on social media. 

Mr. Biden likes to call himself the most pro-union president, and visiting striking workers — a highly unusual move for a president — will certainly send a strong message.

"Tuesday, I'll go to Michigan to join the picket line and stand in solidarity with the men and women of UAW as they fight for a fair share of the value they helped create," he wrote on X, formerly known as Twitter. "It's time for a win-win agreement that keeps American auto manufacturing thriving with well-paid UAW jobs."

UAW President Shawn Fain had invited the president to join the picket line. When a reporter asked the president Friday if he would do so, the president turned the question around, asking, "Would you come with me?"

Last week when he addressed the strike situation, the president said companies involved have made "significant offers," but need to do more. 

"Companies have made some significant offers, but I believe it should go further — to ensure record corporate profits mean record contracts," Mr. Biden said.

The strike began after union leaders were unable to reach an agreement on a new contract with Ford, General Motors and Stellantis. UAW workers want a four-day, 32-hour work week, for the pay of a five-day, 40-hour week, as well as substantial pay raises. They also want more paid time off and pension benefits, instead of a 401K savings plans, among other demands. 

UAW announced Friday that it was expanding its strike to include 38 General Motors and Stellantis parts distribution centers across 20 states. However, Ford was notably not included in the strike expansion as the two sides have had positive contract talks in recent days.  

Nancy Cordes

Nancy Cordes is CBS News' chief White House correspondent.

Twitter