"Sudan has officially notified the United Nations of the end of the term of the United Nations Mission in Sudan (UNMIS) on July 9," Khartoum’s official news agency said said in a statement late on Saturday.
Violence in the contested border region of Abyei following the occupation on May 21 by Khartoum’s troops and tanks have raised fears the two sides could tip back into civil war.
Heavy fighting has forced thousands of people to flee southwards.
Khartoum has received international condemnation for the taking of Abyei, saying that it violated the 2005 Comprehensive Peace Agreement (CPA) signed between the two sides to end two decades of civil war.
Sudan's Foreign Minister Ali Ahmed Karti sent a message to thank UN chief Ban Ki-moon, noting that Sudan has shown "the utmost cooperation, transparency and commitment" to the CPA, the deal that set up the UN force.
UNMIS includes over 10,000 people, most of whom are troops, as well as almost 500 military observers monitoring the peace agreement, and over 1,000 civilian staff.
Although UNMIS headquarters are in Khartoum, most staff are based in the south, which voted overwhelmingly to split from the north in a January referendum.
A separate joint UN-African Union force (UNAMID) operates in the north’s war-torn western Darfur region.