By ROBERT BURNS, AP

WASHINGTON (May 4) - U.S. military commanders in Iraq have decided they need to keep an expanded force in Iraq beyond June and will send 10,000 active-duty Army and Marine Corps troops for one-year tours, Defense Secretary Donald Rumsfeld announced Tuesday.

Another 10,000 active-duty troops will be notified later of their one-year tours in Iraq, the defense secretary said.

Rumsfeld told a Pentagon news conference that he approved the 20,000 extra troops at the request of Gen. John Abizaid, top commander of U.S. forces in the Middle East.

In addition, the Army planned to announce that about 37,000 National Guard and Reserve troops are getting called to active duty to support three National Guard combat brigades that will be sent to Iraq late this year or early in 2005, defense officials said, speaking on condition of anonymity.

There are now about 138,000 U.S. troops in Iraq. The number was to have fallen to about 115,000 this spring, but the latest change of plans would leave the total at about 138,000 after June. That could still change, depending on the security situation between now and June.

About 5,000 Marines and a contingent of about 5,000 soldiers from the 10th Mountain Division, based at Fort Drum, N.Y., will go this summer to relieve the 1st Armored Division and the 2nd Armored Cavalry Regiment, whose soldiers were due to come home in April but were extended until June.

The 10th Mountain Division's 2nd Brigade will go to Iraq. The Marine units are the 11th Marine Expeditionary Unit, based at Camp Pendleton, Calif., and the 24th MEU, based at Camp Lejeune, N.C.

Pentagon officials had said in recent weeks that they were prepared to replace a portion or all of the 20,000 1st Armored and 2nd Cavalry soldiers who are on extended duty in Iraq if Gen. Abizaid believed they were needed.

Abizaid and his subordinate commanders have used the 2nd Armored Cavalry and 1st Armored to deal with outbreaks of violence in and around the Shiite holy city of Najaf and elsewhere in central Iraq.

The Army and Marine Corps are hard-pressed to find substantial additional troops for Iraq duty. Of the Army's 10 divisions, parts or all of nine are already deployed in Iraq or Afghanistan.

The 10th Mountain Division, which is mainly a light infantry unit, has soldiers in both Iraq and Afghanistan.

The Marine Corps has about 25,000 troops in Iraq, mainly in the western area including the restive city of Fallujah.

Details about the 37,000 National Guard and Reserve troops who are being alerted for Iraq duty were not immediately available. They will provide support for the three National Guard combat brigades that were notified earlier this year that they will be going to Iraq for one-year tours late this year or early in 2005. A large proportion of the 37,000 are Army Reserve, one official said.