The United Nations warned Thursday that extreme hunger is pushing people to the brink of catastrophe in areas of South Sudan, as 3.9 million people nationwide now face severe food insecurity. "Since fighting broke out nearly two years ago, children have been plagued by conflict, disease, fear and hunger," Jonathan Veitch, U.N. Children's Fund (UNICEF) representative in South Sudan, said in a statement. "Their families have been extraordinary in trying to sustain them, but have now exhausted all coping mechanisms. Agencies can support, but only if we have unrestricted access. If we do not, many children may die." UNICEF, the Food and Agriculture Organization (FAO), and the World Food Program (WFP) called on the parties to the conflict to grant urgent and unrestricted access to Unity State, where a newly released Integrated Food Security Phase Classification (IPC) analysis shows that at least 30,000 people are living in extreme conditions and are facing starvation and death. "This is the start of the harvest and we should be seeing a significant improvement in the food security situation across the country, but unfortunately this is not the case in places like southern Unity State, where people are on the edge of a catastrophe that can be prevented," WFP Country Director Joyce Luma said in the statement. "The people of South Sudan need peace, nutritious food and other humanitarian assistance and livelihood support to survive and rebuild their lives." Unless unrestricted humanitarian access urgently is granted, the agencies said, food insecurity would deteriorate to famine in parts of Unity State, where assistance has been hampered by violence and lack of access in recent months.