More than 350,000 people have been forced to abandon their homes in three states in Sudan and South Sudan, according to the UN refugee agency.
Two of the states - South Kordofan and Blue Nile - are in Sudan, while the third - Jonglei - is in the world's newest nation.
In Blue Nile and South Kordofan, 100,000 people each have been forced out of their homes. Jonglei, in South Sudan, remains the worst affected, with inter-tribal violence having driven 150,000 from their homes.
Speaking to Al Jazeera on Friday from the World Economic Forum (WEF) summit in Davos, Switzerland, Antonio Guterres, the UN high commissioner for refugees (UNHCR), said that the issues facing the three states are ultimately political ones - about borders, oil, and citizenship status after the formation of South Sudan last summer.
"There is never a humanitarian solution for humanitarian problems. The solution is always political," Guterres said, referring to the situation as a "massive humanitarian emergency".
In the six months since the independence of South Sudan, 360,000 people have arrived in the newly formed nation but Guterres said, "there is almost no economy, no infrastructure", leaving those arriving to the south with little in terms of integration into the young state.
Guterres, who is at the Davos summit to ask for further financial aid for the UN's aid effort, asked for "massive support" from the international community to assist the hundreds of thousands of refugees.
He said the UNHCR is doing all it can do to move the refugees further in-land and farther from the border regions where they could be subject to air raids and inter-community conflicts.
It is "essential to preserve the civilian and humanitarian character of these camps", Guterres said.
Further complicating the status of refugees in the two states is Sudan's announcement on Thursday that starting from April 8, all South Sudanese will be treated as foreigners by the state.
Source: Al Jazeera and agencies