South Sudan and the UN urged Sudan on Wednesday to complete its withdrawal from the disputed Abyei region, as the former civil war foes made slow progress in talks to prevent fresh conflict.
The UN Security Council has demanded both sides remove their troops from the key oil region in an effort to pull the two neighbours back from the brink of all-out war, but Secretary General Ban Ki-moon said Sudan had still not withdrawn its armed police.
Ban "calls on the government of Sudan to withdraw all remaining armed police forces," said UN spokesman Martin Nesirky, a day after the UN peacekeeping mission in Abyei confirmed the Sudanese military had fully withdrawn.
The UN chief called on both sides to show "leadership" in African Union-led talks that resumed Tuesday in the Ethiopian capital Addis Ababa, the first since last month's deadly border fighting.
South Sudan's chief negotiator Pagan Amum said the mood of the talks was "neutral" as they broke for the night Wednesday, with Juba rejecting Khartoum's claims to have fully withdrawn from the area.
Amum said Sudan still had troops in Abyei and a full battalion posted just across the northern side of the border.
"We call on Sudan to withdraw all their forces as they are required by the (UN) resolution," Amum said.
"We made our position very clear that it was a partial withdrawal, Sudan Armed Forces withdrew their forces leaving two platoons."
South Sudan withdrew its troops earlier this month.
Sudan and its southern region fought a war that left more than two million people dead from 1983 until 2005, when South Sudan was given wide autonomy under a deal that paved the way for independence in July last year.
But tensions soon flared again over a series of unresolved issues, including the border, the future of disputed territories and oil.
The South took about 75 percent of the former united Sudan's oil production with it when it separated, but Juba still depends on the north's pipeline and Red Sea port to export its crude.
A protracted dispute over fees for use of that infrastructure led South Sudan to shut its oil production in January after accusing the north of theft.
Abyei, an area the size of Lebanon, is one of the key disputes between the two.
It was due to hold a referendum in January 2011 on whether it belonged with the north or South, but that ballot was stalled over disagreement on who could vote.
Sudanese troops seized the region in May 2011, forcing some 110,000 people to flee southwards, where most remain in impoverished camps.
The breakout of fierce border clashes last month -- the worst fighting since independence -- caused talks between the two to stall.
The Security Council earlier this month ordered both sides to stop fighting and return to talks or face possible sanctions.