Recovery operations were under way near the crash site around the town of Bishoftu, which is 60km (37 miles) south-east of the capital.
The plane was delivered to Ethiopian Airlines on 15 November last year. It underwent a "rigorous first check maintenance" on 4 February, the airline tweeted.
Who are the victims?
Mr Gebremariam told the news conference that passengers from more than 30 countries were on board the flight.
He said they included 32 Kenyans, 18 Canadians, nine Ethiopians, eight Italians, eight Chinese, eight Americans, seven Britons, seven French citizens, six Egyptians, five Germans, four Indians and four people from Slovakia.
Slovak MP Anton Hrnko later confirmed via Facebook that his wife and two children were on the plane.
Three Austrians, three Swedes, three Russians, two Moroccans, two Spaniards, two Poles and two Israelis were also on the flight.
There was also one passenger each from Ireland, Nepal, Saudi Arabia, Djibouti, Belgium, Indonesia, Somalia, Norway, Serbia, Togo, Mozambique, Rwanda, Sudan, Uganda and Yemen.
One person held a UN passport, the airline said. It believed some passengers could have been heading to a session of the UN Environment Assembly which begins in Nairobi on Monday.
A UN source also told Agence France-Presse that "at least a dozen of the victims were affiliated with the UN", and that this may include freelance translators.
World Food Programme executive director David Beasley said seven members of agency staff had died in the crash.
The WFP family mourns today -- @WFP staff were among those aboard the Ethiopian Airlines flight. We will do all that is humanly possible to help the families at this painful time. Please keep them in your thoughts and prayers.