|Diplmats have scurried to reach an accord on north-south border issues and voter eligibility [REUTERS]
Sudan's UN ambassador has warned that conducting a January 9 referendum in Abyei without settling voting rights for competing tribes, as well as the border, will lead to war.
"It is evident that any attempt to conduct the plebiscite before achieving an acceptable settlement between the two parties will mean only a return to war," Daffa-Alla Elhag Ali Osman told a Security Council debate on Sudan on Monday.
The Abyei ballot - scheduled for the same day as people in south Sudan decide whether to opt for independence - is for the people of Abyei to decide whether to remain in north Sudan or join the south.
The separate referendums in southern Sudan and the Abyei region are part of the Comprehensive Peace Agreement reached in 2005, which ended the two-decade old Sudan civil war that left more than two million dead.
Preparations for both votes are way behind schedule, and many Western nations fear conflict if the referendums are delayed.
Status of the Abyei region
New US-brokered talks between Abyei and the Khartoum government, due to start in Addis Ababa, Ethiopia, on Wednesday, have been called off.
The Sudanese ambassador said his government wanted negotiations on the referendums to lead to peace, "not to war, which we have never willingly accepted".
No referendum commission has been set in disputed Abyei and the region's leaders have failed to reach an accord with the Khartoum government on either who is eligible to vote or Abyei's borders.
Local tensions in Abyei, where oil fields are worth hundreds of millions of dollars, have heightened worries over the dispute with Khartoum. The territory is dominated by the Dinka Ngok tribe - who support south Sudan - and Arab Misseriya nomads who migrate with their cattle through the region's rich pastures.
The referendum law gives voting rights to the traditionally southern-supporting Dinka, leaving it up to a commission to decide whether "other Sudanese" are considered residents of the region and can also vote.
The Misseriya have threatened to carry out acts of violence in the district if they are not allowed to vote.
Khartoum's warning comes as the UN peacekeeping chief told the Security Council on Monday that reinforcing the UN force in Sudan cannot prevent hostilities between the north and the south if tensions continue to rise.
Ban Ki-moon, the UN secretary general, said the southern Sudan commission must now work "extremely quickly" if it is to get a vote ready on time.
He also said he was "deeply concerned" about events in the oil-rich Abyei region.
"The continued lack of progress is exacerbating an already tense and volatile situation on the ground," Ban said on Monday in a report to the Security Council.
UN peacekeeping chief Alain LeRoy told the Security Council that the UN mission in Sudan (UNMIS) was considering redeploying troops from the rest of the country to the north-south frontier or calling for international reinforcements.
He said any redeployment would weaken the UN peacekeeping mission in the rest of Sudan but added that "any increase in the number of troops would not enable UNMIS to prevent or contain a clash on the frontier."
"Our best available tool against a return to war remains our commitment in favour of a political agreement ... of the parties on the key pending issues," he said.
LeRoy said there had been no "major military mobilisation" but added that it was "urgent" that progress is made in Abyei talks.
Sudan's UN ambassador spoke out against a reinforcement saying it would be a waste of resources that would not help ease tensions.
Additionally, UN officials have said it would be almost impossible to get significant numbers of new troops to Sudan in time for the referendum.
"The stakes are undeniably high, as failure to meet the deadline for the referendums prescribed by the Comprehensive Peace Agreement could have severe consequences," the UN secretary-general added.
With the south and the north accusing each other of a military build-up on the shared frontier, the UN mission in Sudan UNMIS has already stepped up monitoring along the border and reinforcing "hotspots".