leterThe U.S. military is expanding some rural bases and building others to house thousands of troops displaced by a June deadline to withdraw from Iraq's major cities.

With continual power outages pushing temperatures well above 100 degrees, that can't come soon enough for some soldiers living in sweltering tents at Camp Carver in the small town of Madain, about 15 miles southeast of the capital.

"Can't wait," said Spc. Oscar Garza, 20, of Port Lavaca, Texas, as he carted his bed frame to newly constructed plywood houses with air conditioners elsewhere on the U.S. base.

The Americans have already closed or handed over 60 urban bases since the beginning of the year, with more than 50 others tentatively scheduled to be closed or returned to Iraqi control by the end of June, said Lt. Col. Brian Maka, a military spokesman.

Many of the troops have been transferred to temporary housing on bases just outside cities. They still go into urban areas to support Iraqi security forces, but don't sleep there.

A tent city has popped up at Camp Carver, where the population has more than doubled in recent weeks with the influx of troops from Baghdad, said Lt. Col. Greg Parker, chief of staff for the 225th brigade. The military would not release exact figures, citing security.

Parker, who has been overseeing the expansion at Carver, said engineers have been building housing and fortifying the base since early May.

"This should all be completed well before the June 30 deadline," said Parker, 42, of Gonzales, La.

Spc. Zachary Kyser, 25, of Atlanta, said better housing means more effective soldiers.

"I think we will operate better on our missions once we can get into the new buildings," he said.

Kyser said his unit has moved several times, including most recently from Baghdad to Madain, since the soldiers deployed with the 82nd Airborne from Fort Bragg, N.C.

Under the security agreement that took effect Jan. 1, American troops are required to withdraw from cities by the end of June and leave Iraq completely by the end of 2011. President Barack Obama plans to withdraw all combat troops by Aug. 31, 2010, leaving 30,000 to 50,000 troops to train and advise Iraq's forces. They would withdraw under the 2011 deadline.

The June deadline has strong political significance, giving the Iraqi government a landmark to show its people that Americans are leaving. But sporadic large-scale attacks in recent months have killed hundreds and prompted concern whether Iraq's security forces can adequately take over security.

Prime Minister Nouri al-Maliki has said there is no reason to extend U.S. presence in Iraq's cities, and that Iraqi forces are capable of dealing with threats to security.

Some American troops will remain in the cities in training and advising roles. Military officials have been considering marking those vehicles and uniforms with a patch or emblem that show they are not combat troops, U.S. officials said.

Even as Iraqi and U.S. officials continue to work out details and possible exceptions to the pullback, the military has been rapidly increasing its presence in rural areas.

"Sometimes there are already bases established, and we just need to either increase the actual footprint — the size of the base — or increase the living area," said Col. David Dancer, the operations chief for the 225th Engineering Brigade, which has handled most of the building up and tearing down of bases in and around Baghdad.

"But there are examples of where we are building patrol bases from scratch," Dancer said.

The U.S. military would not say how many new bases were being constructed, but they are believed to be on the outskirts of Baghdad and other big cities.

Army Maj. Gen. David Perkins said there are no plans to close Camp Victory, which houses more than 20,000 troops, and two other smaller bases within Baghdad. Large Marine bases in western Anbar province on the outskirts of Ramadi and Taqqadum, outside of Fallujah, will also remain.

In northern Iraq, the main U.S. air base at Balad and the logistics base on the outskirts at Taji also will stay. In Mosul, U.S. troops operate primarily from the Army's Marez base on the outskirts of the city. In the south, U.S. troops have just taken over for departing British forces and are housed near the airport outside of Basra.

Still to be closed or handed over to the Iraqis are primarily small outposts built during the 2007 surge of U.S. troops into Baghdad, Mosul and elsewhere.

Those outposts enabled U.S. troops to provide greater protection to the civilian population against threats from Shiite and Sunni extremists in their neighborhoods.

In central Baghdad, Capt. Andrew Roher, 35, of Grand Rapids, Mich., watched as all signs of his small base — from its concrete blast walls to concertina wire — were removed from a busy commercial street in an area once a favored target of insurgents.

Bulldozers smashed concrete blocks while welders with torches cut down massive metal poles erected as a barricade to stop potential suicide car bombers.

"Leave no trace is the goal," said Roher, who was heading to a camp outside Madain. "It's kind of like starting over."