The military is reviewing soldiers' complaints that their standard ammunition isn't powerful enough for the type of fighting required in Iraq and Afghanistan, the Army's highest-ranking officer said Thursday.

But Gen. George W. Casey Jr., the Army chief of staff, said it was too soon to say whether the Pentagon will switch.

Current and former soldiers interviewed by The Associated Press said the military's M855 rifle rounds are not powerful enough for close-in fighting in cities and towns in Iraq and Afghanistan.

Speaking with reporters at a conference in Huntsville, Casey said leaders are constantly soliciting feedback from soldiers in the field and were aware of complaints about the M855 ammunition.

"To effectively prepare them we have to adapt as the enemy adapts, and that is some of the feedback we have gotten," Casey said. "We'll evaluate it quickly and then we'll decide how we want to proceed."

But Casey said it would be premature to say if the Pentagon will consider a different type of ammunition.

"I can't tell you exactly what we're going to do," he said.

The M855 rounds were designed decades ago to puncture the steel helmets of Soviet soldiers from hundreds of yards away. Some soldiers said that they are not large enough to stop an enemy immediately in close quarters.

Casey said the military has been evaluating its equipment and practices since the Sept. 11, 2001, terror attacks.

"Technology is pulling us, and what we're learning on the ground in Iraq and Afghanistan is pushing us," he said.