WASHINGTON - For the fifth time in the past year, U.S. commanders running the war in Iraq have told the Army to send more armored Humvee utility vehicles to protect U.S. troops.

Just as the Army was reaching its target of 8,279 factory-built armored Humvees for delivery to Iraq, U.S. Central Command last month raised the bar again, to 10,079, Army officials disclosed Tuesday.

The Army has been accused by many in Congress of lagging behind in providing armor protection for troops, hundreds of whom have been killed or wounded in ambushes and roadside bombs in Iraq. The Army says it has pressed the vehicle manufacturer for as many as possible, and it has been chasing a moving target set initially at 1,407 by commanders in Iraq in August 2003.

When the war began in March 2003, few might have imagined that the all-purpose Humvee, the modern version of the unarmored Jeep, would need to be reinforced in large numbers. But soon they became a prime target of the insurgents' roadside bombs and rocket-propelled grenades.

Ever-increasing requests

By April 2004 the requirement for factory-built armored Humvees had reached 4,454, and commanders in Iraq subsequently raised it to 6,223 in June, 8,105 in August and then to 8,279 in December.

Those are in addition to thousands of regular Humvees to which makeshift armor and ballistic glass have been added to reinforce their doors and windows against the blast from roadside bombs and land mines. Armor also has been added to supply trucks and older troop carriers.

The new armored Humvee target of 10,079 is not expected to be achieved before July, according to Army projections based on the factory's recently increased production rate of 550 vehicles per month. It will take a few weeks beyond July to ship the extras to Iraq.

The increase of 1,800 Humvees includes about 200 for U.S. troops in Afghanistan, where roadside bombs also are a serious threat, according to a defense official who would discuss details only on condition of anonymity. Some of the Humvees for Iraq are to replace those destroyed in battle, the official said.

Imperfect solution

Army officials acknowledge that putting armor on Humvees is not a perfect solution. For one thing, it has added to the wear-and-tear on the heavier vehicles and increased fuel consumption, thereby requiring even more supply convoys that are a common target of insurgents.

"No amount of effort in armoring will make our soldiers completely invulnerable, but we owe it to them to provide the best possible protection," Army Secretary Francis Harvey wrote in a letter to the editor of USA Today on Monday.

During a visit in February to the Ohio plant where the Humvees are produced, Gen. Peter Schoomaker, the Army chief of staff, raised the possibility that the production rate could be accelerated yet again.

The issue of how many armored Humvees are required — and the pace at which they have been produced and delivered to troops — has been one of the most controversial of the Iraq war. Last December, a Tennessee Army National Guard soldier in Kuwait publicly questioned Defense Secretary Donald H. Rumsfeld on what the soldier called inadequate armor against the insurgents.

After that encounter, the Army negotiated a further increase in the production rate, from 450 a month to 550, but the manufacturer could not reach the higher level until March. They are built at a factory in Fairfield, Ohio, by O'Gara-Hess & Eisenhardt, a subsidiary of Armor Holdings.