"We intend to review this proposal together in good faith and then consider what our next steps should be," the union wrote in an update to its membership.
 
The union has been without a new contract for about six months, and health insurance for employees and retirees has been a major sticking point.
 
"Our discussions with U. S. Steel over the past six months have involved continued demands for deep concessions from both active and retired workers and their families," the union said in the statement. "We know that our industry is in the midst of a serious crisis brought on by unfair trade and global overcapacity, but we do not believe that workers and their families should be forced to bear the brunt of these problems."
 
Meanwhile, negotiations between the union and ArcelorMittal are ongoing. In a separate update, the union said there has been some progress in recent weeks, but the company is continuing to seek concessions on insurance benefits for active and retired union members.
 
More bargaining sessions are scheduled to take place this week.
 
"We are still committed to resolving our differences over health care and other issues at the bargaining table," the union said.
 
Steelworkers are also negotiating contract with iron ore producer Cliffs Natural Resources. Those negotiations are also ongoing.