South Sudanese rebel leader Riek Machar has accepted an invitation from the Ethiopian Prime Minister to talks with South Sudanese president Salva Kiir in Addis Ababa next week, a spokesperson for Machar said on Wednesday.

"The Movement welcomes this invitation ... it will go a long way in building confidence in the peace process," the spokesman said in an emailed statement.

The statement said Machar, who is under house arrest in South Africa, had been invited by Ethiopian Prime Minister Abiy Ahmed to attend the talks on June 20. The talks will be led by East African bloc IGAD, the statement said.

There was no immediate comment from South Sudan's government or from IGAD.

The meeting would be the first time that Kiir and Machar, the former vice president of South Sudan, have met since a peace deal between the government and Machar's rebel group fell apart in August 2016.

Tens of thousand of people have died in the civil war that broke out in late 2013 when troops loyal to Machar launched a rebellion against the government. All sides in the now complex and multi-faceted war stand accused by the United Nations and other bodies of committing atrocities against civilians.