Leading UN Security Council powers on Tuesday stepped up calls for Sudan and South Sudan to avert potential sanctions if they miss a looming deadline to make a peace deal.
The Security Council, which has set a Thursday deadline for a deal between the two neighbors, also stepped up pressure on Sudan on Tuesday over restrictions put on the UN mission in the conflict-stricken region of Darfur.
Negotiations between Sudan and South Sudan are deadlocked and Sudan's President Omar al-Bashir turned down a summit on Wednesday with the South's leader Salva Kiir, the foreign ministry in Khartoum said.
Following American calls for the two sides to act on the Security Council deadline, Britain's UN ambassador Mark Lyall Grant urged Bashir and Salva Kiir to show the "statesmanship" needed to overcome their differences.
South Sudan broke away from Sudan in July last year but the two have yet to set a definitive border and are in dispute over oil revenues and citizenship rules. Amid regular clashes, the two sides came close to all-out war this year.
"We had hoped that the two leaders would be getting together early this week in order to try and resolve those outstanding differences," Lyall Grant told reporters.
"We understand that that meeting has not yet taken place. But we urge both leaders to show the necessary statesmanship, to make the necessary compromises so that agreement can be reached on these outstanding issues.
"The Security Council has set a deadline and expects results by that deadline," Lyall Grant warned.
US ambassador Susan Rice also stressed this week that UN resolution 2046, which was passed on May 2 and demanded an accord in three months, allowed for "appropriate additional measures" if the rivals missed the deadline.
The Sudanese foreign ministry said in a statement reported by the official SUNA news agency that African Union mediator Thabo Mbeki, the former South African president, had invited Bashir and Salva Kiir to a summit in Addis Ababa on Wednesday.
The statement said Bashir "apologizes" he could not attend because he would be on a trip to Qatar. The government believes such a summit needs "good preparation," it added.
Mbeki is expected to brief the UN Security Council on August 9 and the British envoy said "the council will obviously decide in the light of that report what next steps to take."
The Security Council on Tuesday extended the mandate of the UN-African Union mission in Darfur, UNAMID, but cut its maximum size from 19,000 troops to 16,200. There will also be 2,310 in the newly configured force.
A resolution setting out the one year extension expressed "deep concern" at restrictions put on the movement of UN peacekeepers by the Khartoum government.
There has been a new surge of clashes between government forces and rebels in Darfur in recent weeks. The UN says at least 300,000 people have been killed in Darfur since local tribes rose up against the Arab-dominated Khartoum government in 2003.
The new resolution said that the UN mission should share information on the presence of Lord's Resistance Army fighters in Darfur, a move which has angered the Sudan government.
Sudan fought against putting the reference to the LRA, which is led by the notorious Ugandan rebel Joseph Kony, in the resolution. UN diplomats said that while there is no credible evidence of Kony's presence in Darfur, they want the UN to be able to investigate any reports.© ANP/AFP