With growing tensions, South Sudan's vice president Riek Machar says he has asked for help from East African countries gathered in the Igad bloc and in particular from Sudan.
Machar, the embattled vice president says he wants Sudanese head of state and top General Abdel Fattah al-Burhan to come to his aid against his President Salva Kiir.
Khartoum was indeed one of the guarantors of the South Sudanese peace agreement, signed in 2018 after five years of civil war.
The new development comes as South Sudan government forces have reportedly surrounded the residence of Riek Machar in the capital Juba. It's not clear if Mr Machar is in the house.
On Friday, the former rebel leader asked regional and international leaders to intervene to end renewed fighting in Unity and Upper Nile states - which are considered his strongholds.
Clashes between South Sudan’s military and forces loyal to Mr Machar have been reported in various areas for weeks - threatening a fragile peace agreement between him and President Salva Kiir
The government has not issued any statement on whether its soldiers have surrounded the premises.