Caroline Anning from the charity Save the Children has warned the situation in South Sudan is similar to the east African famines in the 1980s.
Speaking to ITV News' Dan Rivers she said: "If it continues and we can't get the help we need, we could be looking at a catastrophic famine."
Save the Children are set to launch a worldwide appeal to help and protect the vulnerable children in troubled states of South Sudan, as the country is on the brink of a famine.
Chief executive of the charity Justin Forsyth said:
When I was there in February, I met children separated from their parents by the fighting, children injured in the crossfire and mothers forced to give birth in the bush.
If the planting season is missed, there will be no food, come the harvest in September.
The people of South Sudan need our help now.
Save the Children have launched an appeal for donations for the African nation of South Sudan, which is on the brink of a famine.
The children's charity said that without immediate action the situation will deteriorate catastrophically, as across the world’s youngest nation, 2.5 million children are struggling without the basic means to survive.
ITV News correspondent Dan Rivers reports:
The United Nations has already warned that without a cash injection, South Sudan will face the worst starvation in Africa since the 1980s.
Pete Walsh, Save the Children’s Country Director in South Sudan, has spoken of the need for funds to provide Sudanese families with aid.
He said: "Save the Children’s feeding clinics are dealing with an influx of severely malnourished children, brought in by terrified mothers, many of whom arrive after walking for miles.
"We urgently need to raise funds to provide families with life-saving food supplements."
The United Nations is warning that the food security situation in South Sudan is reaching critical levels.
The UN measures food security and hunger rates in a five phase scale: last week the UN said a third of the population was experiencing emergency levels of food insecurity, they are now reporting more people are in the fourth phase, but not yet at famine.
The next classification will be out in three months time - but if the situation continues in this way then certain areas could deteriorate into famine, which is why the donors are meeting today in Oslo - the situation is urgent and the UN is warning donor countries they must act.
Cholera has broken out in the Juba, the capital of South Sudan where months of civil war has left thousands homeless and disrupted food supplies and health services, according to the World Health Organization.
The confirmed cases come as donors prepare to meet in Oslo to discuss the dire food security situation in the world's newest country.
Cholera is spread through contaminated water and unclean food, so the hundreds of thousands of people internally displaced due to the political crisis are at risk in overcrowded settlement areas. Oxfam's South Sudan director Cecilia Milan said:
"The confirmation of 138 cholera cases in Juba is a stark reminder of the multitude of risks the citizens of this country have been forced to endure since conflict broke out in December 2013.
"There is no question - the international community must act now to prevent a rapidly escalating food crisis - and now potentially a public health emergency - In South Sudan."
The UK will give £60 million to aid agencies working in South Sudan, in an attempt to meet the the "dire" needs of the civilian population fleeing the deadly civil conflict in the newly formed state.
Hundreds of thousands of people have been forced to flee their farms and homes to neighbouring regions and refugee camps, and the situation is expected to deteriorate in the coming months as the rainy season starts. South Sudan's chronic lack of roads and infrastructure will hamper relief efforts.
Development Minister Lynne Featherstone said:
"The situation is dire, getting worse, and 7.3 million people are going to be in need"
None of the money is going through the South Sudan government, instead it will go directly to aid agencies or the UN.
Millions of people in South Sudan are in urgent need of humanitarian assistance to prevent famine, the UN said, as donors prepare to meet in Oslo today to discuss the deteriorating crisis.
The UN said the situation is likely to deteriorate over the coming months.
- Currently, 6.9 million people are acutely food insecure
- 3.7 million people require urgent humanitarian assistance
- From June to August this number will increase to 7.3 million
- Populations face the risk of famine unless humanitarian aid is delivered
Delivering aid to the areas afflicted is complicated and time consuming due to the ongoing affects of the conflict and resulting displacement, and chronic lack of resources and infrastructure.
Norway will host a humanitarian conference for South Sudan in Oslo today, as the UN warned urgent action is needed for millions displaced from their homes who are now facing acute food insecurity.
The meeting comes after the president of South Sudan told the BBC he needed humanitarian assistance.
Salva Kiir said his country faces one of its worst famines unless the current conflict ends. He said it was essential that humanitarian agencies were allowed to work.
The South Sudanese President Salva Kiir and rebel commander Riek Machar have agreed to a ceasefire deal after coming under growing international pressure to end ethnic fighting that has raised fears of genocide in the African nation.
The deal by the two men in Ethiopia was the first time they had met since violence erupted in mid-December following a long power struggle.
Kiir and Machar shook hands and prayed together during the ceremony.
The men also agreed that a transitional government offered the "best chance" to take the country towards elections next year.