Boeing and union negotiators will return to the bargaining table early next week, U.S. federal mediators said on Friday, as the two sides try to end a strike threatening the airplane maker's turnaround.

The U.S. Federal Mediation & Conciliation Service late on Friday said it was convening the parties with a federal mediator after speaking to both sides, less than a day after union members voted by a huge majority to reject Boeing's contract offer and went on strike.

"The parties will resume meetings early next week," it said in a statement. More than 30,000 members of the International Association of Machinists and Aerospace Workers (IAM) who produce Boeing's top-selling 737 MAX and other jets in the Seattle and Portland areas voted on their first full contract in 16 years, with 94.6% rejecting Boeing's offer and 96% favoring a strike. Workers vowed to fight for a better pay offer than the company had made.