Army Col. David Paschal, commander of 1st Brigade, 10th Mountain Division, said in a press briefing that U.S.-led forces in the area "virtually destroy" al-Qaida networks in Kirkuk and violence in the area dropped significantly during the year.

Paschal credited Iraqi national security forces and the Sunni force, Sons of Iraq, with helping U.S. forces secure the area. Roughly 400 members of the Sons of Iraq force entered training to become Iraqi police in areas of western Irbil province, he added.

Irbil provincial officials will take over control of Kirkuk later this year, Paschal said, provided security gains continue.

"That will be based on the capability of the Iraqi security forces to maintain the security gains that we've achieved and continue to defeat the insurgents," he noted.

The Iraqi government and provincial reconstruction teams allocated micro-loans to open small businesses in the area in order to boost the economic incentive for outside investments.