WASHINGTON — Incoming US Defense Secretary Leon Panetta is determined to avoid gutting the American military despite the prospect of difficult budget decisions looming, a Pentagon spokesman said Thursday.

"He (Panetta) believes that it is a false choice between fiscal responsibility and national security," spokesman Douglas Wilson told reporters.

Amid mounting fiscal pressure, the defense budget "will be an important item on his agenda," Wilson said.

"He will take that very seriously. He knows there are difficult decisions to be made," he said.

Panetta "has said publicly, and he will say again, that he intends that there will be no hollow force on his watch."

Panetta, 73, who is stepping down as head of the CIA, is due to take over Friday at 8:45 am (1245 GMT) from Robert Gates, who is retiring after more than four years on the job.

The new Pentagon chief takes the helm against the backdrop of mounting political calls to rein in government spending, including the country's massive defense budget.

The vast defense budget for 2010 stood at $663 billion, accounting for more than 40 percent of the world's military spending, and a growing number of lawmakers say the Pentagon can no longer be excluded from cutbacks.

As secretary, Panetta will also be focusing on the wars in Afghanistan and Iraq and "is committed to succeeding and achieving America's goals on his watch," said Wilson, assistant secretary of defense for public affairs.

Panetta planned to begin his tenure by holding meetings with the military "at all levels," from the top brass to mid-level officers, Wilson added.