JUBA - U.S. Assistant Secretary of State for Population, Refugees and Migration, Anne Richard, on Tuesday called the violence in South Sudan a tragic chapter in the country's short history and pleaded with the warring sides to make peace.

“There is a limit to how much aid can be provided in a year with so many crises around the world," Richard said.

US Official Pleads for End to South Sudan War, Says Aid Not Limitless

"So the best thing ... will be to restore peace to South Sudan, to stop the hostilities and get back to the business of developing this nation into the great nation we all hope it will become,” she said.

US Official Pleads for End to South Sudan War, Says Aid Not Limitless

Richard also visited refugees from Sudan who fled violence at home and are now trapped by the fighting in South Sudan.

US Official Pleads for End to South Sudan War, Says Aid Not Limitless

She said aid agencies are encountering difficulties reaching Sudanese refugees, particularly as most of the camps housing them are in volatile parts of South Sudan.

U.S. Ambassador to South Sudan, Susan Page, agreed with Richard that the

“We are supporting the peace process. We believe that this is the only game in town and we are going to do everything we can to support it," Page said.

As the two women spoke, there were reports of fresh fighting in parts of Unity state.

At least 10,000 people have been killed since South Sudan erupted in violence in December and over 1.1 million have been forced from their homes, according to the United Nations.

Humanitarian agencies have warned that the ongoing fighting has prevented farmers from planting crops, and that could push the country to the brink of famine. There is also a shortfall in humanitarian funding, in spite of the United States pledging another $21.6 million to South Sudan last week.