South Sudan said Thursday it will not withdraw its troops from the oil-rich town of Heglig, a disputed area that borders with Sudan, despite calls from the international community for its soldiers to pull out.

"I will not order the forces to withdraw from Heglig," The President of South Sudan, Salva Kiir, told parliament. "I always say we will not take the people of South Sudan back to war, but if we are being aggressed like this we will have to defend ourselves,"

"I am appealing to the citizens of the Republic of Sudan, especially the mothers, not to allow their children to be dragged into a meaningless war," he said.

Kiir also warned that South Sudanese troops would re-enter Abyei, another disputed region occupied by Sudan, if the UN does not tell Sudan to leave.

Troops from South Sudan first seized Heglig on Wednesday, in the second day of fierce clashes which are threatening to evolve into a full-blown conflict. The region, which lies along the ill-defined border between the two nations, contains an oilfield that accounts for around half of Sudan's oil production making it vital to the north's ailing economy. South Sudan's army claims it as its own but it is internationally recognized as belonging to neighboring Sudan.

Threatening retaliation

Threatening retaliation, Sudan's ambassador to the United Nations, Daffa-Alla Elhag Ali Osman, condemned what he called South Sudan's "heinous attack," adding that he had filed a complaint to the UN Security Council.

"We will decide to retaliate, and retaliate severely, deep inside South Sudan," if the Security Council doesn't address the situation, Ali Osman told reporters.

"We know they are a very fragile state, they have a lot of problems inside. We do not want to escalate this war, which they started, because it is not going serve the interest of either country," he said.

The South in turn has accused Sudan of bombing territory on their side of the border. According to a spokesman of the South's army Col. Philip Aguer, a series of bombing attacks by Sudan on Tuesday wounded four civilians.

International condemnation

As fears mount over the possibility of a full-scale war, both the United States and the United Nations urged the two sides to end the conflict and resume peace negotiations.

US State Department spokeswoman Victoria Nuland condemned South Sudan's seizure of the Heglig region which she described as going "beyond self-defense." She also renewed US condemnation of Sudanese air strikes against civilian areas.

"We urge both countries to return without delay to the negotiating table under" African Union auspices and "use peaceful means, not military action, to resolve outstanding issues," she added.

U.N. Secretary-General Ban Ki-moon, meanwhile, said Wednesday that he was "alarmed by the escalation in fighting" and said both countries should immediately withdraw their forces from each other's territory.

The European Union on Thursday also denounced South Sudan’s presence in the Heglig oilfield and condemned Sudan for launching air raids over South Sudan. It called on both parties “to cease hostilities [and] withdraw forces immediately.”

"The move by the South Sudanese armed forces to occupy Heglig is completely unacceptable. So is continued aerial bombardment of South Sudanese territory by the Sudan Armed Forces," a spokesperson said on behalf of EU foreign policy chief Catherine Ashton.

Since South Sudan gained independence from Sudan in July, it has been embroiled in an increasingly bitter dispute with the North over the fate of the formerly joint oil industry. Conflict also stems from the division of national debt, the status of citizens in each another's territory and the exact position of the border.

sej/msh (AP, AFP, Reuters)