More than 250,000 people living in the Sudanese states of Southern Kordofan and Blue Nile may be facing a major humanitarian crisis as a result of food shortages and ongoing conflict, and the United States is urging Sudan to permit international humanitarian assistance for those in need.

"This could be a major, major calamity. And for Africa, it seems to me this is something that shouldn't be tolerated," Ambassador Princeton Lyman told reporters in Washington January 24, 2012. Lyman is President Obama's special envoy for Sudan.

Serious fighting between residents of the two states and the Sudanese armed forces has prevented many farmers from planting crops or tending to their farms over the past several months. All of the relief supplies that had been provided by groups such as the World Food Programme and the United Nations Children's Fund (UNICEF) have been exhausted and the Sudanese government has prevented them and other international organizations from entering the area.

Lyman said the U.S.-funded Famine Early Warning Systems Network (FEWS NET) is predicting that by March more than 250,000 people will slip from crisis status to emergency status, which is one level short of famine.

The government of Sudan has refused to allow international humanitarian aid, saying the situation in Southern Kordofan and Blue Nile is an internal matter and that they are conflict areas. Lyman warned that in order to prevent a serious situation in March, there will need to be a way to quickly overcome the Sudanese government's opposition to the aid, since it will take several weeks to position food and other supplies before delivery.

"We've been working very hard, leading up to the African Union meeting at the end of this month, to urge the government of Sudan to open up international access and to do so soon," he said. "We have been saying and saying to our African partners that … the world can't stand by and watch famine take place in an area and know nothing's being done."

Sudan's refusal to allow international assistance goes against its duty to protect its own citizens, and the Sudanese government will face negative world opinion if it maintains its opposition while the world watches a famine unfold, Lyman said.

Ultimately a political solution will have to resolve the conflict between the government and residents of the two states, and Lyman said Sudan's response to the food emergency could help that process.

"Making the humanitarian gesture now may create an atmosphere for that, but the most important is for the government to recognize they have this responsibility and the world will respond positively if they say yes," he said.

Lyman said the Obama administration is also working with the African Union to resolve a dispute between the Sudanese government and the newly independent South Sudan over the distribution and financing of oil reserves.

He said an African Union panel is now "very close to a proposal which should be able to reconcile the different interests and come up with a solution," but the United States is concerned over recent escalations in the dispute, including South Sudan's decision to shut down oil production after Sudan imposed a $32-a-barrel surcharge and interfered with South Sudan's pipeline and ships.

"It is a very bad situation, and both sides could get hurt very, very badly," he said.

The United States is also working to calm tensions in South Sudan between two ethnic groups, the Lou Nuer and the Murle, which have recently flared up.

Lyman said the traditional tensions between the groups have resurfaced following South Sudan's independence on July 9, 2011, and they demonstrate the need for the government in Juba to improve its security capabilities to help keep the peace, as well as its outreach to the communities and available conflict resolution and development programs.