U.S. Defense Secretary Chuck Hagel said on Wednesday that the Pentagon will reduce its staff by 20 percent in an attempt to save at least $1 billion over a period of five years.

The move is part of a broader restructuring plan, announced last summer, to reorganize the Pentagon and enforce budget cutbacks in various operations of the defense department. The military is aiming to trim billions from its budget estimates over the next decade, even as Congress is debating measures for its 2014 spending bill, including mandatory cutbacks, also known as sequesters, which could deepen the cuts further.

"Much of these savings will be achieved through contractor reductions, although there will be reductions in civilian personnel," Hagel said, announcing the plan’s details at a news conference with Chairman of the Joint Chiefs of Staff Gen. Martin Dempsey. “Final details will be published when the budget is submitted next year but this reduction will save at least $1 billion over the next five years and result in an OSD staffing of less than 2,200 civilian and military personnel by FY2019,” Hagel said.

Hagel urged Congress to avoid another year of sequestration cuts, pointing out that such a measure in 2013 has put the military’s ability to carry out its future missions at risk.   

"Congress must be a full partner in our efforts to responsibly bring down defense spending and to implement needed institutional reforms that maximize the use of our resources," Hagel said, the Associated Press reported.

Congress has a Jan. 15 deadline to approve its new spending bill, and some lawmakers are pushing for yet another round of mandatory cutbacks.

“If the Department is forced to take the steep sequestration cuts, we could be forced into making more abrupt personnel cuts that would have severe impact on morale and the Department’s overall effectiveness,” a statement from Hagel’s office said.