U.S. President Barack Obama has described the situation in Sudan's Southern Kordofan state as “dire” and pressed the north and south to immediately impose a cease-fire.

Mr. Obama said Wednesday there are reports that attacks are taking place in Southern Kordofan state based on ethnicity. He accused the north's Sudanese Armed Forces of bombing civilians and harassing and intimidating United Nations peacekeepers in the region.

He warned that if a cease-fire is not implemented, the Sudanese government will only face more international isolation.

Mr. Obama also urged both northern forces and troops with the south's Sudan People's Liberation Army to allow humanitarian access to civilians who desperately need help.

The United Nation's estimates some 70,000 people have fled fighting in the north-south border state. Officials say the whereabouts and conditions of many of them are unknown.

Violence has escalated along the north-south border as southern Sudan prepares to declare independence on July 9.

Earlier this week, negotiators reached an agreement on Sudan's disputed Abyei region, where north-south fighting had also broken out.

The north and south agreed to a complete demilitarization of the oil-rich region and the deployment of U.N. peacekeepers from Ethiopia. They also agreed to set up a council to oversee security in Abyei.

President Obama praised the Abyei agreement and expressed hope that a cease-fire in Southern Kordofan will allow peace negotiations to move forward.