Rome, Feb 20 .- Some 100,000 people are affected by a famine and another million at risk of it due to war and economic collapse in South Sudan, three United Nations agencies warned on Monday.

The Food and Agriculture Organization of the United Nations (FAO), United Nations International Children's Fund (UNICEF) and World Food Programme (WFP) said in a statement that urgent action was needed in order to prevent people from dying of hunger.

"Famine has become a tragic reality in parts of South Sudan and our worst fears have been realized. Many families have exhausted every means they have to survive," said FAO Representative in South Sudan Serge Tissot, according to the statement.

The declaration of famine means people have already started to die of hunger in the African nation.

"The people are predominantly farmers and war has disrupted agriculture. They've lost their livestock, even their farming tools," Tissot said.

While famine has been declared in several parts of Unity State in the north, the number of those affected was expected to increase to 5.5 million in July if nothing is done to alleviate the food crisis.

The only way to prevent the expansion of the famine, according to the UN organizations, was to scale up humanitarian assistance for those affected.

"There is only so much that humanitarian assistance can achieve in the absence of meaningful peace and security," WFP Country Director Joyce Luma said of the "man-made famine."

South Sudan has been gripped by conflict since Dec. 2013, when President Salva Kiir, of Dinka ethnicity, accused Vice President Riek Machar, of the Nuer ethnic group, of attempting a coup d'etat.

Last year, 130,000 South Sudanese citizens fled to Sudan due to the conflict and food insecurity, according to the United Nations Office for the Coordination of Humanitarian Affairs. (EFE)