African Union mediator Thabo Mbeki has urged the United Nations Security Council to take action to stop the fighting between Sudan and South Sudan, warning that both sides are locked in a "logic of war" with hardliners increasingly in control.
Security Council members promised to urgently discuss how to address the crisis, including the possibility of sanctions, said Susan Rice, the US ambassador to the UN and current Security Council president.
Rice briefed reporters on Tuesday about former South African president Mbeki's closed discussion with the council via videoconference.
Mbeki, along with Haile Menkerios, a special UN representative to Sudan, "described a disturbing situation in which both sides are locked in, and I quote, 'a logic of war'," Rice said.
"They stressed that hardliners are winning the day in both Juba and Khartoum and urged the Security Council to engage with both governments directly to convince them to walk back their positions."
A border conflict between Sudan and South Sudan escalated when the South seized the oil town of Heglig. Sudan has responded with fierce aerial bombardment of the town.
The fighting is the bloodiest since South Sudan broke away from Sudan last July and became the world's newest nation. The crisis threatens to widen into all-out war.
Rice said Mbeki told the council that Khartoum believed South Sudan was seeking regime change in its northern neighbour "and that if that was the case, then the objective of Khartoum would also be regime change" in the South.
"Frankly, one would hope that that is rhetoric and not the objective or the purported objective of either side," Rice said.
Rice said Security Council members reiterated their demands that the South's forces withdraw from Heglig and that the Sudanese armed forces end their bombardment.
She provided no details on the sanctions the council might consider.
The ambassadors of South Sudan and Sudan each described their countries as the victim.
South Sudan's UN ambassador, Agnes Oswaha, insisted that her country "took Heglig out of self-defence and also because the Sudan army has been using the area as their operation base to wage their attacks on the Republic of South Sudan".
"We have reiterated our position over and over calling upon Khartoum to return to the negotiation table," Oswaha told reporters after Mbeki's briefing. "Our intention is not regime change."
Sudan's UN ambassador, Daffa-Alla Elhag Ali Osman, said any sanctions the Security Council discusses should be directed at South Sudan because of its seizure of Heglig.
"We are not an aggressor. We are the victim," he told The Associated Press, adding that Sudan would return to talks when the government of South Sudan "returns to its senses and accepts a withdrawal".
The fighting has displaced more than 100,000 people.