Reuters reports Sudan has asked a joint U.N.-African Union peacekeeping mission in its western Darfur region to prepare plans to leave, a senior official said on Friday, amid a dispute between the United Nations and Khartoum over an alleged mass rape in the area. Sudan initially refused to let the UNAMID peacekeepers visit a village to investigate the rape allegations. They were later allowed in and found no evidence that Sudanese troops had raped about 200 women and girls there, but the U.N. complained of a heavy military presence during interviews. "Sudan formally requested - I formally requested - that UNAMID make an exit strategy. That does not mean it will pack up its things and say goodbye," foreign minister under-secretary Abdallah al-Azraq told reporters, suggesting the mission's departure would take a long time.