The delegation of South Sudan’s former vice-president, Riek Machar, attending the Addis Ababa peace talks has said that Uganda must stop supporting government forces as a major condition for signing a ceasefire to end fighting in the nation.

Spokesman for the delegation, Mabior Garang, said: “These are sticking points that the government does not want to move away from.”

The peace talks are being sponsored by the regional African body IGAD in the Ethiopian capital Addis Ababa.

Uganda’s President Yoweri Museveni admitted for the first time Thursday night that he was helping South Sudanese President, Salva Kiir, to fight the rebel forces.

Ugandan officials had earlier denied taking any part in combat, insisting their troops were evacuating stranded Ugandans and helping protect the airport and the presidential palace in South Sudan’s capital Juba.

Kampala’s military involvement has annoyed Ethiopia, which is hosting the peace talks aimed at ending the fighting between Kiir’s forces and supporters of Machar.