A new round of talks between South Sudan's President Salva Kiir and rebel leader Riek Machar will take place next week in the Sudanese capital, the Sudanese government said on Friday.

Kiir and Machar met in the Ethiopian capital this week, the first time the two men had met since 2016 when a peace deal collapsed spectacularly, leading to the deaths of hundreds of people in the South Sudanese capital of Juba.

But after the meeting convened by Ethiopian prime minister Abiy Ahmed, representatives of Kiir and Machar poured cold water on hopes for an end to a five-year civil war, by dismissing proposals for a "bridging" administration put forward by regional body IGAD.

Sudan is a member of IGAD, which has led the faltering peace process for South Sudan.

The war that broke out in 2013, less than two years after oil-rich South Sudan gained independence from Sudan, has caused the deaths of tens of thousands of people and triggered the biggest displacement crisis in Africa since the Rwandan genocide in 1994.

Despite the apparent failure of this week's efforts to get Kiir and Machar to find common ground in Addis Ababa, the Sudanese Foreign Affairs Ministry said in a statement on Friday: "Preparations are afoot to give a new impetus to this new round of talks and ensure a successful outcome."

The ministry said next week's talks would be convened by Sudanese President Omar al-Bashir, a key player in South Sudan's history.

Before the people of South Sudan voted for secession and declared independence in 2011, the region fought a brutal conflict for more than two decades against the Sudanese armed forces and militias led by Bashir.