General James Ajongo dies in a Cairo hospital where he was undergoing treatment.
General Ajongo was promoted as head of the South Sudan army in May 2017, replacing Paul Malong.
President Kiir declares three days of national mourning to honour the veteran commander and orders all South Sudanese flag be flown at half-staff.
South Sudan’s army chief General James Ajongo has died in a Cairo hospital where he was undergoing treatment.
South Sudan Information Minister, Michael Makuei Lueth on Friday confirmed the death of the army chief and called upon the general public to remain calm.
"It is with heavy heart that I announced the untimely death of General James Ajongo, the Sudan Peoples' Liberation Army's Chief of Defense forces," Makuei said.
He said the government has declared three days of national mourning to honour the veteran commander and ordered that the South Sudanese flag be flown at half-staff.
"I have declared a three days official mourning and ordered all South Sudanese flags to be flown at half-mast. I call up on all South Sudanese to honour the memory of General James Ajongo and join us in official observance," President Salva Kiir said in a brief statement.
General Ajongo was promoted as head of the South Sudan army in May 2017, replacing Paul Malong.
Ajongo joined the Sudan People's Liberation Army, the formal name of the South Sudanese military, in 1983, when the SPLA was still a rebel group fighting for independence from Sudan.