New York - A United Nations Security Council deadline for Sudan and rival South Sudan to reach a peace accord passed on Thursday, but they are to get more time to pursue fragile negotiations, diplomats said.

“Clearly Sudan and South Sudan have not fulfilled all the conditions laid down, although progress has been achieved,” said France's UN ambassador Gerard Araud, the current president of the 15-nation council.

The Security Council passed a resolution on May 2 giving the rivals, who at the time were near to all-out war, three months to settle their differences.

Former South African president Thabo Mbeki has been leading a mediation effort with negotiators from the two sides in Addis Ababa.

Diplomats following the talks said they were “very fluid”. Sudan President Omar al-Bashir this week turned down a last-minute summit with his rival from South Sudan, Salva Kiir, the Khartoum foreign ministry said.

Pressure will now increase with the African Union's Peace and Security Council to discuss the case on Friday when US Secretary of State Hillary Clinton is expected to arrive on a visit to South Sudan.

Clinton “will express our continued concern about the lack of movement in the resolution of the key issues that divide the two countries”, a high-ranking US official said.

The United States has been a key backer of South Sudan, which split from Sudan in July last year. The two never formally set their border or agreed how to divide revenues from oil reserves that straddle the two sides.

Clashes have broken out all along the disputed border and South Sudan has stopped oil production because of the revenue battle.

Sudan has been accused of staging air raids in the South, while the Khartoum government has stepped up accusations that South Sudan is backing rebels in its South Kordofan and Blue Nile states.

But the violence has eased in recent weeks and both sides have moved most of their forces out of the disputed flashpoint territory of Abyei.

African Union mediator Mbeki is to brief the Security Council on the status of talks on August 9.

“It will be for the council to decide how to maintain the rather shaky momentum that has emerged,” Araud said, adding that the UN body will take account of recommendations made by the AU Peace and Security Council.

The resolution passed in May allowed for consideration of sanctions if the peace accord was not reached, but the French envoy said there was a “consensus” at the Security Council that sanctions were not yet necessary.

“But we do need to maintain pressure on the parties involved so that they continue negotiations,” he added. - Sapa-AFP