The United Nations' human rights chief says South Sudan's president, Salva Kiir, and rebel leader Riek Machar do not appear concerned about a possible famine in the country.
Navi Pillay told reporters in Juba Wednesday that she was "appalled" after holding separate meetings with the two leaders.
She said both men were lukewarm to a U.N. official's call for a "month of tranquility" so people can plant fields and prevent food shortages.
Ethnic violence and clashes between rebel and government forces have killed thousands and displaced about 925,000 people within South Sudan. U.N. agencies are working to assist some 5 million people in need of humanitarian aid.
On Thursday, U.S. Secretary of State John Kerry meets with East African leaders in Addis Ababa in hopes of advancing stalled South Sudan peace talks.