Boeing has announced that it would temporarily halt production of the 737 MAX jets beginning in January 2020 after American regulators ruled out flight clearance for the globally grounded aircraft.

The decision was driven by a number of factors, including the extension of the US regulators' certification process into 2020, as well as the uncertainty about the timing and conditions of the plane model's return to service.

FAA chief Steve Dickson disclosed that there was no clear timeline for when the 737 Max will be re-certified and that there are 10 to 11 milestones left to complete before it can be approved.

Dickson's comments squashed Boeing's hope of getting the planes cleared for resumed service before the end of this year.