Boeing's West Coast factory workers walked off the job early on Friday after they unanimously rejected a contract, halting production of the company's best-selling 737 MAX jet.

Boeing's west coast factory workers walked off the job early on Friday after overwhelmingly rejecting a contract deal, halting production of the planemaker's strongest-selling jet as it wrestles with severe output delays and heavy debt.

A strike at Boeing "could go on for a while" as workers are confident they can get bigger wage increases and an improved pension, union leader Jon Holden said in an interview with National Public Radio (NPR) on Saturday.