The Pentagon announced Monday that more than 92,000 troops will be in the next rotation of U.S. forces in Iraq, and Defense Secretary Donald H. Rumsfeld said its exact size will not be decided until after the Dec. 15 election of a new Iraqi government.

The Pentagon said it has identified some of the major combat units that will deploy, starting in mid-2006 as part of a rotation that will run through mid-2008, including a National Guard brigade from Minnesota.

It said the identirengthened to about 160,000 this fall out of concern for extra violence during voting in October and December.

The number of troops in future rotations will depend on conditions, including the severity of the insurgency and the strength of Iraqi security forces, as well as the recommendations of U.S. commanders, Rumsfeld said.

"We know we're going to bulk up for the elections, and we know we're going to go back down to some level after the elections," Rumsfeld said in a telephone call to The Associated Press. During the call, Rumsfeld complained that an AP report gave the mistaken impression that the Pentagon has already decided to reduce troop levels below 138,000 next year.

Separately, a senior Army general said there is a growing momentum in the training of Iraqi security forces, which now total about 100,000 army soldiers and about 111,000 police forces. In a detailed briefing before a group organized by the Center for Strategic and International Studies, a think tank, Lt. Gen. David Petraeus said the goal is to have a combined total of 230,000 army and police by the December election.

Petraeus left Iraq last summer after a year in command of training programs for the Iraqi security forces. His briefing charts said training and equipping of the Iraqi army should be done by January 2007, and by March 2007 for the Iraqi police services. The total number of forces is to reach 325,000 by July 2007.

The Pentagon hopes to be able to reduce U.S. troop levels as Iraqi security forces become more capable of defending their own country, but it is unclear when that point will be reached.

Officials also disclosed that U.S. commanders in Iraq decided they would not need one brigade — normally numbering about 3,500 soldiers, until early next year. It had been scheduled to deploy to Iraq before the Dec. 15 election. That unit, the 1st Brigade, 1st Infantry Division, based at Fort Riley, Kan., will deploy after the election instead.

The troop rotation announcement identified only six combat brigades, including one from the National Guard, that will deploy over a two-year period beginning in mid-2006. Currently there are about 17 brigades in Iraq. Monday's announcement did not include any Marine Corps units, although they apparently will be added later.

The forces "as presently envisioned" number 92,000 soldiers, the Pentagon said.

Rumsfeld, appearing before reporters with British Defense Minister John Reid prior to announcing the troop rotation details, stressed that conditions on the ground in the months ahead will determine any changes in U.S. force levels.

"We're aware of the interest in the press in the mid-to-longer-term levels of U.S. forces and coalition forces in Iraq, but I would caution that it would be a mistake to draw conclusions about such matters when reviewing the force rotation announcements that will be made later today," Rumsfeld said.

"We continue to transition and transfer additional responsibilities to the Iraqi security forces, and the people of Iraq continue to meet the political milestones that they have established," he added. "As these and other conditions are met, Gen. (George) Casey will continue to assess the capabilities that he believes he will need and make recommendations as to the levels he believes will be needed in the period over the coming months."

The Pentagon said the following major units will deploy as part of the 2006-2008 rotation:

— 1st Brigade, 34th Infantry Division, Minnesota Army National Guard.

— 2nd Brigade, 1st Infantry Division, Schweinfert, Germany.

— 3rd Brigade, 2nd Infantry Division, Fort Lewis, Wash.

— 3rd Brigade, 82nd Airborne Division, Fort Bragg, N.C.

— 3rd Brigade, 25th Infantry Division, Schofield Barracks, Hawaii.

— 2nd Brigade, 10th Mountain Division, Fort Drum, N.Y.

— 13th Corps Support Command, Fort Hood, Texas.

— Division headquarters, 25th Infantry Division, Schofield Barracks, Hawaii.

The announcement said, without elaboration, that Rumsfeld decisions "may result in changes to this rotation and may affect units now being identified and advised to prepare to deploy."