Those in the rural areas are most at risk.
Aid agencies warned that about 8.1 million South Sudanese are at risk of being food insecure.
Some 28,000 people are facing serious starvation in South Sudan’s Aweil State, a minister has said.
Those in the rural areas are most at risk, Aweil State Minister of Agriculture John Amar Akook added.
The Integrated Food Security Phase Classification also said that some 275,000 people have been facing a food crisis between May and July in the same area.
Mr Akook, quoted in the local English daily Juba Monitor, added that the food gap has contributed to looming poverty and hunger in rural areas after seasonal rains caused flooding. People living in the lowlands were most affected -- they were unable to cultivate their farms as a result of the floods.
Recently, aid agencies warned that about 8.1 million South Sudanese are at risk of being food insecure.
The humanitarian crisis in South Sudan deteriorated after the outbreak of civil war in 2013.
The UN rated the humanitarian crisis as one of the worst in the world.