North American airlines that operate the 737 MAX 8 said they were monitoring the investigation.
Under global rules, responsibility for leading the crash investigation lies with Ethiopia but the U.S. National Transportation Safety Board (NTSB) will also participate because the plane was designed and built in the United States. He said the plane "is now right inside the ground" and it was not possible to identify whether it was an emergency landing or a crash.
State-owned Ethiopian is one of the biggest carriers on the continent by fleet size.
All 157 people on board the Ethiopian Airlines (ET) flight that crashed earlier Sunday are confirmed dead, Ethiopian state television reported.
A general view shows the scene of the Ethiopian Airlines Flight ET 302 plane crash, near the town of Bishoftu, southeast of Addis Ababa, Ethiopia on March 10, 2019.
Both Addis Ababa and Nairobi are major hubs for humanitarian workers, and some had been on their way to a large United Nations environmental conference set to begin Monday in Nairobi.
The flight had unstable vertical speed after take off, the flight tracking website Flightradar24 tweeted.
The Boeing 737 Max 8 plane heading to Nairobi left Ethiopia's Addis Ababa International Airport this morning but came down within six minutes, killing all 149 passengers and eight crew members on board. The senior Ethiopian pilot, who joined the airline in 2010, sent out a distress call and was given clearance to return to the airport, the airline's CEO told reporters.
The plane took off at 8:38am (05:38 GMT) from Bole International Airport and "lost contact" six minutes later.
Sunday's crash comes as the country's reformist young prime minister, Abiy Ahmed, has vowed to open up the airline and other sectors to foreign investment in a major transformation of the state-centered economy.