WASHINGTON (AP) — The Defense Department has begun planning for the roughly $500 billion in personnel and program cuts over a decade that will be needed if Congress and the White House fail to reach a deal that would avoid the double hit of tax hikes and automatic spending reductions dubbed the "fiscal cliff."

Department spokesman George Little said the cuts would be "devastating to our national defense."

As the White House and members of Congress continue to wrangle over how best to find as much as $1.2 trillion in savings over the next 10 years to avert the fiscal cliff, Little said the Pentagon started more detailed discussions this week on how to slash 9.4 percent of its budget across the board.