The United Auto Workers’ leader said negotiations for a new labor contract with Detroit’s three car companies have been progressing, but he threatened to expand the union’s now six-week-long strike if they don’t move more.

UAW President Shawn Fain said during a livestream to members Friday that General Motors, Ford Motor and Chrysler-parent Stellantis have each offered 23% wage increases for factory workers over more than four years. That would amount to record contracts for those employees, but the companies still have room to sweeten their offers, he said.