WASHINGTON (Reuters) - U.S. planemaker Boeing ( BA ) faces a "long road" to address safety issues, the head of the Federal Aviation Administration said on Thursday as it prepares to receive the company's plan to address concerns.

In late February, FAA Administrator Mike Whitaker gave Boeing ( BA ) 90 days to develop a comprehensive plan to address "systemic quality-control issues" and barred it from expanding 737 MAX production.

Whitaker told ABC News the 90-day plan, due next week, "is not the end of the process. It's the beginning and it's going to be a long road to get Boeing ( BA ) back to where they need to be making safe airplanes".