|A referendum is also being planned for the oil-rich Abyei, claimed by both the south and the north [AFP]
World leaders attending the UN General Assembly in New York are set to discuss the upcoming referendum on the independence of southern Sudan amid fears that a break up of the giant oil-rich country could plunge it into violence.
The presidents of Ethiopia, Kenya, Rwanda and Uganda - all Sudan's neighbours apart from Rwanda - are among the African officials attending Friday's special session. They will be joined by ministers from Brazil, Britain, Canada, Egypt, France, Germany, India and Norway.
Sudan will be represented by Ali Osman Taha, its vice-president from the north, and the meeting "will be an unprecedented show of will and unity", according to Samantha Power, an aide to Barack Obama, the US president, who will also attend the meeting.
Obama and Ban Ki-moon, the UN secretary-general, met on Thursday in advance of the crisis meeting at the UN headquarters.
The meeting comes days after Hillary Clinton, the US secretary of state, called Sudan a "ticking time bomb" while Ban said it is one of his "top priorities".
The summit is to "encourage the north and south to work constructively together. They have had interactions but it needs to be more sustained," Philip Crowley, the state department spokesman, said.
Fears that south Sudan - along with Abyei, which sits astride the oil-rich border between the south and north, could seek to break unilaterally from Khartoum, sparking more conflict in the war-torn nation - have been raised repeatedly at the United Nations this week.
The referendum, slated for January 9, is part of a 2005 peace accord that ended two decades of civil war in the south in which two million people died. Under the agreement, south Sudan manages its own political affairs but is not fully independent of Khartoum.
The New York-based Human Rights Watch (HRW) said it was concerned about impunity for human rights violations by security forces across Sudan, restrictions on civil and political rights, and the treatment of minority groups throughout Sudan.
The two parties to the peace agreement - the ruling National Congress Party (NCP) in the north and the south's ruling Sudan People's Liberation Movement (SPLM) - should state publicly that they will not expel each other's minorities in the event of secession, HRW said ahead of the summit.
According to diplomats and UN officials, preparations are hopelessly inadequate and Friday's meeting will aim to pressure Sudan to get the vote back on track and make it both peaceful and credible.
Voter registration has not started and may now not be ready on time, according to diplomatic sources. There is not even a north-south border, they said.
Some diplomats suspect Omar al-Bashir, the president, has been deliberately dragging his feet over the referendum.
"I came away from the last Security Council briefing very worried about what is going to happen," one UN ambassador said this week, speaking on condition of anonymity.
The US, Britain and Norway last week sent a letter to Sudanese leaders urging them to make sure the referendum date is maintained.
The US, which has a special envoy for Sudan, has put a huge amount of diplomatic energy into its campaign.
On Tuesday, Clinton met Taha, the north's vice-president, in New York and the White House said Obama would send a "forceful message" to the Sudanese at Friday's UN meeting.
In further preparation for the meeting, Clinton also met Salva Kiir, the president of southern Sudan.
Sudan's key oil production, especially supplying China, its strategic position in Africa near Somalia and the Democratic Republic of Congo, the Darfur conflict in western Sudan, and the past North-South civil war has focused worries about the votes.
There are fears the SPLM could declare unilateral independence if the referendum is significantly delayed.