Boeing's CEO Dennis Muilenburg apologized on Thursday for lives lost in deadly crashes in Ethiopia and Indonesia, but said the plane manufacturer remains confident in the "fundamental safety" of the 737 MAX aircraft.

Upcoming software updates to its automated control system will make it "among the safest airplanes ever to fly," Muilenburg said.

The report from Ethiopia's Aircraft Accident Investigation Bureau spelled more bad news for Boeing, as it recommended that Boeing re-examine its Maneuvering Characteristics Augmentation System (MCAS).

"We at Boeing are sorry for the lives lost in the recent 737 MAX accidents," Muilenburg said in the statement, adding that a software update is expected to be finished and certified in the coming weeks.

The update intends to "eliminate the possibility of unintended MCAS activation and prevent an MCAS-related accident from ever happening again," he said.