That could appeal to some Republicans who criticize Obama for setting drawdown targets based on what they say is a political calendar instead of security after 13 years of war.

Carter also expressed interest in expanding counter-terrorism cooperation with Pakistan and advancing efforts to arm and integrate Sunni tribal forces into Iraq's battle against Islamic State militants.

Still, it remains to be seen whether Carter will depart from longstanding Obama administration positions. Carter is an administration insider who has toiled away in high-ranking positions within the Pentagon in recent years.

His roles include deputy defense secretary -- the Pentagon's No. 2 job -- from 2011 to 2013 and the Pentagon's chief weapons buyer from 2009-11 when he led a major restructuring of the F-35 fighter jet program.

"I would think we will see more of continuity than we will see divergence," said William Perry, a former US defense secretary and mentor to Carter.

Carter's hearing will be closely watched by Lockheed Martin Corp, Boeing Co and other big weapons makers, which are waiting for clues about Carter's priorities and his commitment to new procurement programs, including a new long-range bomber and the Air Force One replacement.

Like Hagel, Carter criticized across-the-board spending cuts imposed by Congress but also singled out the need for greater reform of defense spending, already underway.

"I cannot suggest support and stability for the defense budget without at the same time frankly noting that not every defense dollar is spent as well as it should be," he says in prepared opening remarks.