US Defense Secretary Leon Panetta scolded Republican lawmakers Thursday for adding what he deemed to be unnecessary expenses to the Pentagon's budget, warning it could lead to "gridlock."

The Pentagon chief spoke after the Republican-led House Armed Services Committee approved a defense budget that added funds for a study on a possible East Coast missile defense site and for modernizing US Navy cruisers that were due to be retired.

The panel approved a bill for a base defense budget of $554 billion, which committee Chairman Buck McKeon says is about $4 billion more than what President Barack Obama's administration wants to be spent for fiscal 2013 in order to meet cost-cutting targets.

The lawmakers also authorized $88.5 billion for the war in Afghanistan and other counterterrorism efforts, in line with the Pentagon's request.

"My concern is that if Congress now tries to reverse many of the tough decisions that we reached by adding several billion dollars to the president's budget request, then they risk... potential gridlock, because it's not likely that the Senate will go along with what the House did," Panetta told reporters.

He warned that the bill, which must be voted by the entire House before heading to the Democrat-led Senate, "could force the kind of trade-offs that could jeopardize our national defense."

The chairman of the Joint Chiefs of Staff, General Martin Dempsey, said the committee's extra funding for a study on a possible new missile defense site on the US East Coast was not necessary.

"In my military judgment, the program of record for ballistic missile defense for the homeland, as we've submitted it, is adequate and sufficient to the task," he said.

"I don't see a need beyond what we've submitted in the last budget."

Fiscal pressure has forced military chiefs to scale back projected spending by $487 billion over the next decade, a task they have described as tough but manageable.

But a threat of dramatic defense cuts also looms on the political horizon.

If Congress fails to agree by January 2013 on how to slash the deficit, dramatic defense reductions of about $500 billion would be automatically triggered under a law adopted last year.

"The Department of Defense and I believe the administration are not going to support additional funds that come at the expense of other critical national security priorities," Panetta said, warning that "there is no free lunch here."

"And if members try to restore their favorite programs without regard to an overall strategy the cuts will have to come from areas that could impact overall readiness."

The panel's bill also cancels an increase in military health care benefits.