South Sudanese President Salva Kiir has said he would refer oil arguments with neighbouring Sudan to African Union mediators, vowing not to take the country back to war.
Speaking on Monday, he said Sudan's President Omar al-Bashir was mobilising for war, something he would not inflict on South Sudan if it could be avoided.
"The people of South Sudan should remain calm and patient as we work with the African Union to resolve this impasse with Sudan," Kiir told reporters, while condemning the "aggressive attitude" of Khartoum.
Sudan on Sunday put on hold nine security and economic pacts with South Sudan, including vital oil shipments, but said Khartoum remained committed to good relations if Juba ended support for rebels.
The move followed an order from Bashir to shut the pipeline carrying South Sudanese crude for export.
South Sudan denies supporting fighters in the north, and in turn has accused Khartoum of backing rebels on southern territory.
"This latest turn of events brings into question the credibility" of the African Union mediators, Kiir said, but added "we remain optimistic that they will intervene accordingly.
"We urge both regional and international governments to diplomatically engage with Sudan in order to protect the lives of the citizens of both nations, and to encourage Sudan to engage in peaceful dialogue with their internal rebellion," Kiir said.
"While President al-Bashir has declared jihad and is mobilising for war, I maintain my pledge to you and the world that I will not take the people of South Sudan unnecessarily back to a state of war," he added.
'Producing still on'
South Sudan's oil minister said on Monday the country would continue to pump oil to Sudan despite a threat from its neighbour.
South Sudan has piped around 7m barrels of crude to its neighbour since resuming production in April, Stephen Dhieu Dau told reporters.
"This is increasing every day," the oil minister said.
"This is not the final figure because producing is still on, we have not received any official communication from the government of Sudan so we are still producing."
He gave no production figure but officials said last month the country was pumping around 200,000 barrels a day from its main Palouge Field in Upper Nile state.
After months of intermittent clashes, Sudan and South Sudan agreed in early March a detailed timetables for normalising relations by setting up a border buffer zone and implementing key pacts.
South Sudan separated with most of Sudan's oil production, but the export infrastructure remained under northern control.
The two sides had not been able to agree on how much Juba would pay to use the pipeline.
Both impoverished nations stand to earn billions of dollars if the oil flows.