NAIROBI, Sept. 19 (Xinhua) -- The fresh fighting between the government and rebel forces in the north of Sudan's war-torn Darfur region has severely restricted the delivery of critical aid, said a statement from the Office of the UN Resident and Humanitarian Coordinator Ameerah Haq issued on Friday.

    The office urged the warring parties to have ceasefire and allow unhindered aid access to the restive region.

    "The United Nations urges both parties to immediately cease hostilities and requests humanitarian access to the affected areasin North Darfur,"Haq said.

    The humanitarian coordinator visited El Fasher,the capital of North Darfur state, and called on all parties to comply with theirresponsibilities to protect civilians and allow humanitarian access.

    A hybrid UN-African Union peacekeeping mission to Darfur, which has so far reached less than half its mandated deployment of 26,000 troops and police officers, has not yet established a presence in the area of the latest clashes because of security reasons.