Sudan says it is pulling out of talks with South Sudan, as the two countries' forces clash in a disputed border region.

The announcement Wednesday came as South Sudan's army claimed control of the oil-producing town of Heglig.

In an interview with VOA Sudan's deputy foreign minister, Ramatallah Mohammed Osman accused the south of aggression.

He said, “Regarding the talks, I don't think in this situation there will be talks. How can you talk with people who have occupied your land?”

Osman also called for the troops' quick removal.

“But now we ask the international community to exert pressure on the government of South Sudan to withdraw its forces immediately from this part of Sudan.”

Sudan is accusing South Sudan of launching attacks in Heglig and surrounding areas with the help of local rebels who have been fighting Khartoum since June of last year. The south says it pursued Sudanese troops into Heglig after repulsing an attack Tuesday.

The African Union issued a statement Wednesday urging both sides to respect each other's territorial integrity. It also called on the south to remove its troops from Heglig.

The AU is trying to mediate bitter disputes between the two Sudans stemming from the south's independence last year. But the talks in Ethiopia's capital have made little progress.

Key issues include borders, the sharing of oil revenue and the status of nationals in each other's territory.

Both countries have suggested the possibility of renewed war. Before their separation, north and south Sudan fought a 21-year civil war that ended with a 2005 peace agreement.

The AU's Peace and Security Panel says that in the wake of the fighting, Sudan has ruled out any possibility of a summit between its president, Omar al-Bashir, and South Sudan President Salva Kiir.

The two men were scheduled to meet last week but the summit was cancelled because of an earlier round of fighting over Heglig.

The United Nations Security Council is scheduled to hold a closed-door session on Sudan Wednesday. That meeting was called to discuss the situation in Abyei, another contested region.