EL PASO, Texas - The Pentagon will withdraw two brigade combat teams from Europe as part of an effort to slash $487 billion in spending over the next decade, but will maintain a strong presence by rotating units in and out of the region, Defense Secretary Leon Panetta said on Thursday.

Panetta told the Defense Department press service in an interview that the two brigade combat teams being withdrawn by the Army would be replaced by rotational units.

A brigade combat team usually has about 3,000 to 5,000 personnel, depending on makeup. Four brigade combat teams are currently stationed in Europe - three in Germany and one in Italy.

Some 40,000 soldiers and 100,000 dependents are currently stationed in Europe. Troops rotating into and out of the region would not be accompanied by their families, which would help reduce the military's costs.

The withdrawal of the two brigades from Europe is part of a new strategy unveiled last week aimed a guiding cuts to defense spending over the next decade as the military tries to pare $487 billion in projected spending from its budget.

The strategy calls for the US military to shift its global focus to the Asia-Pacific, even as it moves to shrink the overall size of the force in order to achieve the spending cuts it was asked to implement by Congress and President Barack Obama.

The strategy calls for the military to expand its emphasis on cyberwarfare and unmanned aircraft. But the size of the US Army and Marine Corps would shrink 10 percent to 15 percent under the plan.

The force would no longer be large enough to conduct long-term counter-insurgency operations like those in Afghanistan.

Administration sources had said some US forces in Europe were likely to be removed. But Panetta's remarks on Thursday were the first confirmation of the decision by the Pentagon leadership.

"Our budget is basically designed to reinforce the new missions we are talking about and that agile, deployable and ready force that has to move quickly," the American Forces Press Service quoted Panetta as saying.