Ethiopia will hold a state funeral for late Prime Minister Meles Zenawi, who died Monday after 21 years in power, with regional heads of state expected to attend, officials said Saturday.

During the funeral, to be held on September 2, a procession will convene at Addis Ababa's Meskel Square, a vast space in the centre of the city often used for public rallies, and proceed with the coffin to the National Palace.

"It will go from Meskel Square to the palace," said State Minister of Foreign Affairs Berhane Gebre-Christos told reporters.

Several African heads of state are expected to attend, including Rwandan President Paul Kagame, Uganda's Yoweri Museveni, Mwai Kibaki of Kenya and Salva Kiir of South Sudan, according to their respective ambassadors, who met Friday with Berhane to pay their respects.

It is not yet known where Meles -- a former Marxist rebel brought up in the Ethiopian Orthodox Christian tradition -- will be buried.

Former Ethiopian emperor Haile Selassie was buried in 2000 at Addis Ababa's Trinity Church, 25 years after being killed during the dictatorship of Mengistu Haile Mariam and his remains stashed in a palace toilet.

Officials could not confirm whether Meles would also be buried in Trinity Church.

Thousands of people gathered at the National Palace this week to view Meles's casket, draped in an Ethiopian flag and surrounded by bunches of flowers and a portrait of the late leader.

Mourners wailed and fell to the ground as they passed the coffin, which rests at the top of a set of carpeted stairs in the palace grounds.

Deputy Prime Minister Hailemariam Desalegn is expected to be sworn into office to replace Meles at an emergency session of parliament, which could happen "at any time" according to government spokesman Bereket Simon.

A parliamentary meeting to swear in Hailemariam was scheduled to take place on Wednesday but cancelled in order to give the nation a chance to mourn Meles, Bereket said.

"The only thing we are waiting is for the right time, the party has to lead this massive and overwhelming outpouring of Ethiopian people to the streets to express their condolence," Bereket said.

Mengistu, toppled by Meles in 1991, still lives in comfortable exile in Zimbabwe.