“According to the Ethiopian constitution the deputy prime minister will have to go to parliament and take the oath, and the government is organising the parliament to be summoned as soon as possible,” Bereket Simon said.
Parliament is normally scheduled to convene after the Ethiopian New Year on September 11.
Hailemariam, 47, has been deputy prime minister and foreign minister since 2010, and was previously special advisor on social affairs to Meles.
Unlike many core members of the ruling party, he does not hail from the far north of the country but from the Southern Nation, Nationalities and People’s Region, the most populous of Ethiopia’s nine ethnic regions.
Ethiopia has declared a state of national mourning, but has not fixed a date for a funeral.
“Up until the funeral takes place, the Ethiopian government council of ministers have decided to make it national mourning time for the remembrance of the Prime Minister,” Bereket added.
“We will have his whole funeral proceedings according to a plan prepared by a committee which deals with this.”
He added that Ethiopia was calm following the news of the death.
“I assure you everything is stable and everything will continue as chartered by the Prime Minster,” Bereket said.
Meles had not been seen in public for two months, and had been reported to have been sick in a hospital in Brussels. He was last seen in public at the G20 summit in Mexico in June.
Bereket gave no details of the illness but said Meles had been ill for the past year.
“He has been struggling to be healthy in the last year… one of the best things about him was that he never considered that he was ill and he was up to the job every time, every day, every evening,” he added.
“Illness has never been a hindrance for him, but he has been quite ill for some time.”