Boeing chief Dennis Muilenberg said "we are doing everything we can to understand the cause of the accidents in partnership with the investigators, deploy safety enhancements and help ensure this does not happen again".
"The truth about the crash is indeed contained in the flight recorders", he said.
"Following the banning of the 737 MAX from the airspace of many countries, including America, which is the country that builds it, this type of plane is now banned from Iranian airspace", Jafarzadeh said.
The decision Thursday comes a day after the USA, where Boeing is based, issued an emergency order grounding the 737 Max 8.
Debris at the scene of the plane crash in Ethiopia
The system seems to have forced the nose of the jet down in a mistaken belief the plane was at risk of stalling.
The source reported being told that the American investigators left the BEA Thursday night after 12 hours of "doing nothing". It will take several days to complete the first readings from the boxes, French aviation officials said. Ethiopian authorities are leading the crash probe and it will also include the U.S. National Transporation Safety Board.
The flight data and cockpit voice recorders were handed over to France's Bureau of Enquiry and Analysis for Civil Aviation Safety (BEA) on Thursday.
Both crews asked permission to return to the airports from where they had departed.
The report cited "a person who reviewed air traffic communications" from Sunday's flight saying controllers noticed the plane was moving up and down by hundreds of feet. "They're not there to protect any company, or any airline, or anybody else and i'm gonna be scrutinizing to make sure that there wasn't any undue influence", said Rep. Peter DeFazio.
Messi leads demolition of Lyon to take Barca to Champions League quarters
The 31-year-old has set up 12 goals this season, with Chelsea's Eden Hazard following closely behind with 11 assists to his name. It will be interesting to see whom the Blaugrana side face.