South Sudan rebel leader Riek Machar left Khartoum Tuesday for South Africa to seek medical treatment.
His departure came just two month after he went to the Sudanese capital for medical attention.
The former South Sudan first vice-president addressed the press at the Khartoum airport before his departure.
"I thank the government of Sudan for the hospitality and I want to announce here that I am heading to South Africa for medical treatment,'' said Dr Machar.
The rebel leader recently declared that he would work to bring down the government of President Salva Kiir.
His pronouncement occasioned a diplomatic row between Juba and Khartoum, but the latter has reassured that it would not allow any aggression or opposition activities against South Sudan from its territories.
Dr Machar was treated at a Khartoum hospital in August after he fled South Sudan following the eruption of war in the new state in July.