CHICAGO (Reuters) - The head of the Federal Aviation Administration said on Thursday that Boeing ( BA ) has not yet resumed producing 737 MAX airplanes following a machinists strike, but plans to begin later this month.

FAA Administrator Mike Whitaker this week met with Boeing ( BA ) CEO Kelly Ortberg and toured Boeing's ( BA ) 737 plant in Renton, Washington, as it boosts oversight following the strike, which ended Nov. 4.

Whitaker said Boeing's ( BA ) plan is to slowly restart production later this month and he plans another trip to Seattle in January as the company ramps up.

"The thing that I was most struck by was we're four weeks post-strike and they're still not producing airplanes, because they're focused on their workforce, the training, making sure they have the supply chain sorted out," Whitaker told Reuters in an interview.

Boeing ( BA ) did not immediately comment.

Whitaker capped production at 38 737 MAX planes per month in January after a door panel missing four key bolts flew off an Alaska Airlines 737 MAX 9 in midair that month, exposing serious safety issues at Boeing ( BA ). He declined to say when he thought the FAA would restore Boeing's ( BA ) ability to produce more than 38 planes per months, but said he would be surprised if it was less than "multiple months" before they get close to the 38 maximum.

Whitaker said he expected to receive a proposed 737 MAX engine deicing as soon as later this month that has been holding up certification of the MAX 7. "We have done everything we can our side awaiting that solution on the deicing" Whitaker said. "That solution has to go into the current production line and then has to be part of the certification (application)."