"The process of identifying the victims will take at least five days", Ethiopian Airlines spokesman Asrat Begashaw said in Addis Ababa.
The causes of the two crashes are under investigation, but amid the uncertainty a growing number of countries and airlines have grounded the plane, one of Boeing's newest and most important models.
At the opening of the United Nations assembly in Nairobi, delegates paid their respects with a moment of silence, according to press reports from the Kenyan capital.
Describing how the FAA functions, Goelz said the agency - which has sent a team of investigators to the crash site in Ethiopia - is "data-driven" and doesn't make decisions on anecdotal evidence.
A video posted on Twitter during this week claiming it shows the moment when the Ethiopian Airlines plane crashed on Sunday killing 157 people was debunked.
US President Donald Trump spoke to Boeing Chief Executive Dennis Muilenburg and got assurances the aircraft was safe, two people briefed on the call said.
Concerns over the safety of the Boeing 737 Max 8 has prompted more than 40 airlines and aviation authorities to ground the aircraft or stop it flying in their airspace.
"It's just hard to accept that this has happened", he said in a telephone interview from Kenya on Tuesday. The agency says there are 74 Boeing 737 Max 8 and Max 9 planes registered in the USA, with 387 worldwide. Both planes crashed shortly after takeoff.
But October's Lion Air crash in Indonesia sparked a debate on automation, particularly over a software system created to push the plane down to stop a stall during flight. Kayak.com was the first big site to say it would modify filters to allow customers to exclude particular types of planes from queries.
"I can't begin to explain how much I miss you and how different life will be without your handsome laugh and your tight hugs".
Mr GebreMariam told CNN his airline's pilots had received additional training on the flight procedures involving the 737 MA after the Lion Air crash.
The Federal Aviation Administration also backed the jet's airworthiness and said it was reviewing all available data.
He said he was taken to the airport police department to verify his identity and was questioned for being the lone passenger who did not board the doomed flight.
The plane's passengers and crew came from at least 35 different nations, and included almost two dozen United Nations staff. Each flight crashed minutes into its journey, during a phase of flight where fatal accidents are not at their most common.
Kenya suffered the greatest fatalities - 32 - in the crash, the flight having been headed to Nairobi's Jomo Kenyatta International Airport.
Five members of the Hamilton family killed in the Ethiopian crash: Ann Wangui Karanja, 60; Ryan, 7; Kerri, 4; and Carolyne Karanja, 34, and Rubi, 9-months.