The United Nations says while more than one million children have fled South Sudan's escalating violence, the same number of children have been displaced within the country due to the conflict.
The figures illustrate "how devastating this conflict has been for the country's most vulnerable," said Leila Pakkala, UNICEF's regional director for Eastern and Southern Africa.
"That refugee children are becoming the defining face of this emergency is incredibly troubling," said Valentin Tapsoba, the African Bureau Director of the U.N.'s refugee agency. "No refugee crisis today worries me more than South Sudan."
Pakkala says "the future of a generation is truly on the brink."
The U.N. organizations on the frontline of the humanitarian crisis in South Sudan are themselves facing a funding crisis.
UNICEF, the U.N. organization that provides humanitarian aid to mothers and children in developing countries, said in a statement Sunday that it has only 52 percent of the $181 million needed to address the acute needs of the South Sudanese refugees until the end of the year.
UNHCR, the U.N.'s refugee agency, meanwhile, says it has just 11 percent of the $781.8 million needed to help the fleeing South Sudanese refugees.
South Sudan has been beset by violence for more than three years because of a political rivalry between the young country's two leaders.
The power struggle between President Salva Kiir, an ethnic Dinka, and his former deputy, Riek Machar, a Nuer, broke out in December 2013 after the president accused Machar and 10 others of attempting a coup d'état.
Fighting has split the country along ethnic lines, displaced millions of people and caused severe food shortages.