The cuts would be on top of $487 billion the Pentagon has already slashed. Defense Secretary Leon Panetta has warned sequestration reductions will destroy President Obama's new defense strategy and weaken national defense.

"I can't reduce the budget by half a trillion dollars and frankly not increase risk," Panetta said.

On this, the president's adversaries on Capitol Hill agree.

Republican Kelly Ayotte is a member of both the Senate Budget and Armed Services Committees. She worries the perception of a weakened military will encourage terrorists and rogue nations to attack U.S. interests.

"The numbers speak for themselves, but the message that it sends in terms of encouraging other people to act further and act badly is not a good one in terms of the safety of America," Ayotte said.

Nearly 80,000 Defense Department civilian jobs are at risk. Pentagon officials hope to avert layoffs. They are instead considering asking employees to take up to a month off from work without pay.