Former Vice President Riek Machar will return to Juba next week for the first time since the start of South Sudan's civil war, according to a senior opposition politician.

Machar fled Juba at the outset of the war in December 2013 and later formed the SPLM-IO rebel group, which signed a peace deal with the government in August this year.

According to Oyai Deng Ajak, former national security minister and a member of the group of exiled politicians known as the 'SPLM-G10', Machar will be accompanied by Ethiopian Prime Minister Hailemariam Desalegn.

He told Radio Tamazuj from the Ethiopian capital Addis Ababa that the one-day visit aims at determining final arrangements for implementation of the peace deal to resolve the crisis in South Sudan.

“Riek will go next week with the prime minister of Ethiopia. He will go for one day and he will return on the same day back to Addis Ababa,” said the former minister.

Oyai explained that the visit will serve as a sign of reassurance that the armed opposition are serious about implementing the peace agreement.

Separately, Oyai stressed the readiness of the SPLM-G10 to return to Juba if the government is serious about implementing peace. But he denounced the proposal by Salva Kiir to increase the number of states in South Sudan to 28, calling it a breach of the peace agreement signed in August.

“They have violated the Addis Ababa agreement. They brought 28 states instead of 10 states that we agreed on in Addis Ababa... but all of these things we will talk about when we go to Juba,” he said.

File photo: Riek Machar (right) signs an agreement on 9 May 2014 witnessed by Hailemariam Desalegn (left)