The presidents of northern and southern Sudan are close to reaching an agreement on pulling troops out of the disputed Abyei border region before the south secedes on July 9.

VOA correspondent Peter Heinlein reports that northern leader Omar al-Bashir and southern leader Salva Kiir began talks Sunday in Ethiopia's capital, Addis Ababa.

He says they met with a high-level African Union panel that included Ethiopian Prime Minister Meles Zenawi and former South African president Thabo Mbeki. The discussions are set to continue Monday.

Mr. Mbeki said the two sides are also discussing the possible deployment of an Ethiopian-led peacekeeping force to the north-south boundary.

Northern forces seized control of oil-rich Abyei last month, prompting tens of thousands of residents to flee the area.

Also Sunday, United Nations Secretary-General Ban Ki-moon urged all parties to stop hostilities in the area, as he welcomed the talks in Addis Ababa.

Separately, northern troops have been fighting armed groups in the border state of South Kordofan for more than a week. On Sunday, the north's army denied reports that two of its warplanes were shot down in South Kordofan.

The north and south previously fought a 21-year civil war that ended in 2005. The unrest in Abyei and South Kordofan has raised fears that Sudan could sink back into a prolonged conflict.

U.S. Secretary of State Hillary Clinton is due to arrive in Addis Ababa just as the Sudanese summit is ending. Clinton, who is on a three-nation African trip, is scheduled to deliver a foreign policy address at African Union headquarters.

She is expected to meet with south Sudan President Kiir, and possibly with Sudanese Vice President Ali Osman Taha.

She is not expected to meet with President Bashir, who is wanted by the International Criminal Court for alleged war crimes in Sudan's Darfur region.