By Alex Dziadosz and Jeremy Clarke
KHARTOUM/JUBA (Reuters) - North and south Sudan have agreed to negotiate an end to the crisis in the disputed Abyei region, the southern vice president said Monday, in an effort to defuse tensions ahead of the south's scheduled secession.
Khartoum moved tanks and soldiers into the fertile, oil-producing Abyei region on May 21, causing tens of thousands of people to flee and stoking fears the two sides could return to full-blown conflict.
South Sudan's Vice President Riek Machar flew to Khartoum this week to meet with his northern counterpart following the northern advance. He said the two sides would form a committee to "resolve the issue of Abyei," but did not give details.
His visit came after Khartoum threatened to clear southern-allied armed groups from Southern Kordofan and Blue Nile, raising the specter of fresh conflict.
The two areas are inside the north's territory but are home to thousands of fighters that fought against Khartoum during the last civil war. They lie near a 1956 internal border drawn shortly before Sudan became independent.
"We are committed to imposing security and law north of the 1956 line, and we will not permit the presence of any forces on northern land," Ismat Abdel Rahman Zein al-Abdin, chairman of the northern joint chiefs of staff, said last week.
Officials with the southern ruling party, known as the Sudan Peoples' Liberation Movement (SPLM), say troops in those areas are northerners, and so Juba cannot ask them to withdraw.
"Even if we told them, 'Come back,' they would not accept to go to the south, because they are foreign there," Machar said.
Popular consultations are planned to decide the two regions' relationship with Khartoum, but they have yet to take place. Machar said joint north-south military units should be allowed to operate in the regions until consultations are held.
Southerners voted overwhelmingly for independence in a January referendum promised by a 2005 peace deal that ended decades of civil war, but issues such as the position of the shared border and oil-sharing have not been settled yet.
Analysts say the northern government could be trying to secure a strong bargaining position in talks over oil-sharing and other issues ahead of the split.
"They (the north) are trying to corner the SPLM. They are putting the SPLM in a very difficult situation in Abyei, Southern Kordofan and Blue Nile," Fouad Hikmat of the International Crisis Group said.
Tensions were ignited in oil-producing Abyei, also coveted for its fertile grazing land, after an attack on a convoy of northern troops and U.N. peacekeepers that was blamed on southern forces on May 20.
Khartoum occupied the town the following day and has since defied calls by the United Nations, United States and southern Sudanese officials to withdraw, saying the land belongs to the north.
Abyei was a major battleground during the last civil war between north and south. It is used all year round by the south-linked Dinka Ngok people and part of the year by northern Arab Misseriya nomads.
The south has so far sought to downplay tensions over Abyei. Kiir said Thursday there would be no war over the incursion and that it would not derail independence.
(Additional reporting by Khaled Abdelaziz, Editing by Lin Noueihed)