The Pentagon is sending an additional brigade of the Army's 82nd Airborne Division (search) to Iraq and extending the deployment there of another 82nd Airborne unit in what officials said Thursday is a minor adjustment to their plan for rotating fresh forces into Iraq next year.

Senior U.S. military officials said part of the 1st Brigade of the 82nd Airborne, which had not been scheduled for duty in Iraq, will begin heading there in January for a four-month tour. The 3rd Brigade of the 82nd, which was scheduled to depart Iraq in February, will remain until April.

The officials, who discussed the matter on condition of anonymity, said these moves were deemed necessary to maintain continuity during the rotation of forces, which runs from January to May.

There likely will be more changes to the overall rotation plan in the weeks ahead, the officials said.

Not the entire 1st Brigade of the 82nd Airborne will be deployed, the officials said. Roughly "a couple of thousand" will go, rather than the entire unit of 3,500 soldiers, they said.

The 1st Brigade had returned from a six month tour of duty in Afghanistan (search) last August, at approximately the same time the 3rd Brigade began its deployment to Iraq.

Officials said the decision to send the 1st Brigade was related to a requirement for more extensive training of an Army National Guard (search) unit -- the 81st Infantry from Washington state -- than originally planned. The 81st is now scheduled to deploy to Iraq in March instead of January.

There now are roughly 123,000 U.S. troops in Iraq, and once the rotation is complete in May there are expected to be about 110,000.

Defense Secretary Donald H. Rumsfeld visited the home of the 82nd Airborne, Fort Bragg, N.C., on Thursday.