Two U.N. agencies say they have assisted more than 500,000 people in parts of South Sudan hit hardest by the country's nine-month conflict.
UNICEF and the World Food Program say 100,000 children are among those they have assisted with food, sanitation supplies, and vaccinations for polio and measles.
The agencies say about 1.8 million South Sudanese have fled their homes because of the conflict, and of those, 1.4 million remain displaced within South Sudan. The statement says more than half of the internally displaced are children.
The agencies say much of their work has taken place in the states of Jonglei, Upper Nile, and Unity.
On Monday, the United States said it is giving an additional $83 million in emergency aid for refugees fleeing the fighting in South Sudan.
The unrest stemmed from a political dispute between President Salva Kiir and his former deputy, Riek Machar. Ethnic violence and fighting between pro- and anti-government troops has killed an estimated 10,000 people. Peace talks in Ethiopia have made little concrete progress.