New York: The UN Security Council demanded on Thursday that Sudan and South Sudan stop border clashes which it said threatened to return the east African neighbours to a full-scale war.
A statement from the 15-nation body also insisted that Khartoum stop air strikes and Juba withdraw troops from a vital oil field.
Fighting along the ill-defined border between the former civil-war foes has led to a standoff over Heglig oil field after it was seized on Tuesday by troops from South Sudan, which declared independence last year.
Distrust runs deeps between the neighbours, who are at loggerheads over the position of their border, how much the landlocked south should pay to transport its oil through Sudan, and the division of national debt, amongst other issues.
"The recent violence threatens to return both countries to full-scale war and the period of tragic loss of life and suffering, destroyed infrastructure, and economic devastation, which they have worked so hard and long to overcome," a statement from the Security Council said.
"The Security Council demands a complete, immediate, and unconditional: end to all fighting; withdrawal of (South Sudan`s Army) from Heglig; end to (Sudanese Armed Forces) aerial bombardments; end to repeated incidents of cross-border violence between Sudan and South Sudan; and an end to support by both sides to proxies in the other country," it said.
The Council demanded that both countries redeploy their forces 6 miles (10 km) outside a north/south borderline determined in 1956 and take immediate steps to establish a safe demilitarised border zone.
It termed the situation a "serious threat to international peace and security" and warned it would take further steps as necessary, but gave no details on what those might include.
South Sudan has accused Sudan of launching air strikes on some of its major oilfields. Sudan has denied launching air strikes but said its ground forces had attacked southern artillery positions that had fired on the north.
Sudan`s UN Ambassador Daffa-Alla Elhag Ali Osman said South Sudan must heed to the UN call.
"If they don`t ... we will reserve our right to exercise the right of self-defence and we will chase them out," he told reporters. "Not only that we will hit deep inside the south."
Osman described claims of aerial bombardments of South Sudan by Sudan as "fiction”.
South Sudan`s UN envoy Agnes Oswaha told reporters Juba supported the UN call for an end to the fighting and was prepared to negotiate with Khartoum.
However, she added: "This can only come about if the outstanding issues between Sudan and South Sudan ... are resolved immediately."
Oswaha said South Sudan would withdraw from the Heglig oil field provided a "mechanism was put in place to guarantee the area could not be used to launch further attacks against South Sudan" and a neutral international force was deployed to the area until the neighbours reached a settlement on the disputed territory.
South Sudan seceded from Sudan in July, six months after a referendum agreed under a 2005 peace deal that ended decades of civil war that killed more than 2 million people.