Gen. George Casey told reporters he had discussed the issue with Gen. Peter J. Schoomaker on Wednesday and that the Army chief of staff believes he can still sustain the mission in Iraq.
"The forces are stretched ... and I don't think there's any question of that," Casey said. "But the Army has been for the last several years going through a modernization strategy that will produce more units and more ready units."
He reiterated he would only recommend reductions in the more than 130,000-strong U.S. military presence in Iraq based on the situation on the ground.
"We have to admit the fact that the light, high-tech force that Secretary Rumsfeld advocates is simply a dinosaur," said Retired Army Col. Mitch Mitchell a CBS News Military Analyst. "That's not going to work for our commitments for the future. In the future we'll have more enemies not fewer."
On Tuesday, an unreleased study conducted for the Pentagon said the Army wasbecause of the wars in Iraq and Afghanistan.
A day later, Secretary of Defense Donald Rumsfeld disputed that, asserting that "the force is not broken."
"This armed force is enormously capable," Rumsfeld told reporters at a Pentagon briefing. "In addition, it's battle hardened. It's not a peacetime force that has been in barracks or garrisons."
Reports suggesting that the U.S. military is close to the breaking point are "just not consistent with the facts," he said.
The study found that the Army may not be able to retain and recruit enough troops to defeat the insurgency in Iraq, CBS News correspondent Barry Bagnato reports.
Another study, headed by Clinton administration Defense Secretary William Perry, warns adversaries might be emboldened by the American weaknesses, reports Bagnato. The report also urges new spending on troop training and equipment.
The Army fell more than 6,600 recruits short of its goal of enlisting 80,000 troops last year, the first time it missed its annual target since 1999 and the largest shortfall in 26 years.
But the Army exceeded its monthly recruiting goal in December for the seventh consecutive month, though some of those targets were lowered from last year's. It will have to increase its recruiting pace, however, to meet its target of 80,000 that it has set for the budget year ending next Sept. 30.
A new law will let the Army attract older recruits, raising the top age from 35 to 42. In addition, financial bonuses for enlistments and re-enlistments have increased.
Casey spoke after attending a ceremony in which Polish troops transferred leadership of the south-central region of Iraq to Iraqi forces, the first such handover since the war began in 2003.
He rejected the idea that early troop withdrawals came because of strain on the military.
"That's not true, and the recommendation to begin the reduction of forces came from me based on our strategy here in Iraq," Casey said. "I made my decision based on operational reasons and I'll continue to do that. As I've said all along, I will ask for what I need to accomplish this mission."