Two and a half million South Sudanese people will be living in severe hunger over the next three months, a new report on food security in South Sudan said.

The Integrated Phase Classification (IPC), a monitoring mechanism comprising humanitarians and food security experts from government and international organizations, said that up to 80% of people in some parts of the country are still not able to plant crops.

South Sudan has faced a major hunger crisis over the last year because the war prevented farmers from cultivating. The country averted famine in the second half of 2014 thanks to adequate rains and the world's largest humanitarian effort which cost over a billion dollars to bring food to people in need.

The new IPC results show that South Sudan still faces major food insecurity.

In a statement responding to the IPC results, humanitarian agency CARE said South Sudan "is now more vulnerable to food crisis than ever before" because people's coping mechanisms are already stretched thin from last year.

In Jonglei state's Duk County, people are surviving on water lilies, wild fruits, and hunted animals, and are selling off their last belongings to buy food, CARE reported.

“If communities in these [conflict-affected] states are further isolated by fighting, the results could be catastrophic,” said Aimee Ansari, CARE's country director for South Sudan.

Aid agency Oxfam warned: "These latest figures on food security demonstrate that South Sudan is still in jeopardy. The classification has stayed at a serious point for a number of months - and getting food to where it is needed is extremely hard."

Oxfam said it is "seriously concerned" that food insecurity will reach emergency levels in May and June.

The agency noted that while the food situation has improved in some areas of South Sudan, elsewhere it is getting worse because people cannot safely access aid due to fighting.

“The only way to end the violence and suffering of the people of South Sudan is by reaching a lasting peace deal," Oxfam said. "We appeal to all parties to the conflict to deliver on their promises."

Humanitarians have appealed for $1.81 billion to respond to South Sudan's humanitarian crisis in 2015, saying $600 million dollars are needed immediately to prepare for the rainy season, including by pre-positioning food stocks in remote areas.

Photo: Child in Ganyiel, Unity State, April 2014 - International Rescue Committee (IRC)/World Food Programme (WFP)