IGAD proposes giving President Salva Kiir's government a majority in the National Assembly and the presidential cabinet, and Riek Machar's opposition group a majority in the three states most affected by the crisis.
East African bloc IGAD says it will continue to lead peace talks for South Sudan, but will work alongside mediators from a dozen organizations and countries, including the United States, United Nations and China.
IGAD, the regional bloc brokering peace talks for South Sudan, gives the two sides a fortnight to hammer out the details of a transitional government and warns of action against anyone who violates the latest peace deal.
The lead negotiator for the opposition says his side did not sign the so-called matrix because it was being forced on them by IGAD mediators.
Ethiopian Prime Minister Hailemariam Desalegn, who chairs the regional bloc that is mediating South Sudan peace talks, warns there will be consequences if the latest agreement is not respected.
Regional group IGAD and the U.N. Mission in South Sudan say the ceasefire monitor died of natural causes, after he and the monitoring team he was traveling with were detained by members of the opposition in Bentiu.
The lead negotiator for the opposition, Taban Deng Gai, says the government side has not shown up for the talks since last week.
