The Pentagon is looking to reduce the size of its nearly 800,000 civilian workforce by 40,000 to 50,000 employees over the next five years, mainly through attrition as it closes bases and consolidates healthcare facilities, the department's comptroller said on Wednesday.

"I would hope that given the time to prepare, we could do this through attrition, but we aren't far enough along to really know for sure as to how we do it," said Undersecretary of Defense Robert Hale, the Pentagon's comptroller.

Hale said the employee reductions were tied to Pentagon plans to close excess bases and consolidate healthcare facilities, which were proposed on Wednesday and would have to be accepted by Congress before going into effect.