As President Bush weighs new strategies for Iraq, the Army's top general warned Thursday that his force "will break" without thousands more active duty troops and greater use of the reserves.

Noting the strain put on the force by operations in Iraq, Afghanistan and the global war on terrorism, Gen. Peter J. Schoomaker said he wants to grow his half-million-member Army beyond the 30,000 troops already added in recent years.

Though he didn't give an exact number, he said it would take significant time and commitment by the nation, noting some 6,000 to 7,000 soldiers could be added per year.

Officials also need greater authority to tap into the National Guard and Reserve, a force once set up as a strategic reserve but now needed as an integral part of the nation's deployed forces, Schoomaker told a commission studying possible changes in those two forces.

"Over the last five years, the sustained strategic demand ... is placing a strain on the Army's all-volunteer force," Schoomaker told the commission in a Capitol Hill hearing.

"At his pace ... we will break the active component" unless reserves can be called up more to help, Schoomaker said.

Speaking to reporters afterward, Schoomaker said Gen. George Casey, the top commander in Iraq, is looking at several options in Iraq, including shifting many troops from combat to training Iraqi units. Schoomaker said that while ground commanders assess their options, the military is more interested in getting the Iraqi security forces up to speed than sending more U.S. troops.

"Focus less on trainers," he said, and more on "how we generate Iraqi output."

The Army in recent days has been looking at how many additional troops could be sent to Iraq, if the president decides a surge in forces would be helpful. But, officials say, only about 10,000 to 15,000 troops could be sent and an end to the war would have to be in sight because it would drain the pool of available soldiers for combat.

"We would not surge without a purpose," Schoomaker told reporters. "And that purpose should be measurable."

Schoomaker's comments come as Bush reviews options for the foundering Iraq war, including suggestions he send more U.S. troops to the increasingly violent country and accelerate the training of Iraq's own security forces.