The United Nations says ongoing conflict and a weak harvest in South Sudan have put millions of people on the brink of a severe hunger crisis.

A joint report released Wednesday by the World Food Program (WFP) and the Food and Agriculture Organization (FAO) says the number of food-insecure people in South Sudan has risen to 4.7 million — an increase of more than 40 percent since last year.

The report says of those, about 1 million are in urgent need of food assistance. But it warns that figure could double because of high food prices and population displacements caused by conflict in multiple regions.

The study also says poor rainfall was responsible for a weaker-than-usual harvest, which drove up food prices.

It says normal market conditions could make up for the insufficient food supply, but that the closure of border crossings with neighboring Sudan has disrupted markets.

Fighting along the border with Sudan and a number of internal conflicts between the government and rebel groups in Jonglei, Upper Nile and Unity states have forced tens of thousands of South Sudanese to become displaced in their own country.

Sudan and South Sudan separated last year, following years of ethnic and religious conflicts, but tensions have continued over accusations that each side is arming the other's rebel groups.

The World Food Program's South Sudan director, Chris Nokoi, described the situation as “dire,” saying the international community is “running out of time” to prevent a humanitarian crisis in the country.

The U.N. agency says it needs additional funding of at least $160 million to reach its goal of reaching 2.7 million people with food assistance.

Meanwhile, the Food and Agriculture Organization is looking for $23 million in funds to continue to provide agricultural support and other assistance ahead of this year's rainy season.