Chuck Hagel (center). Reuters

President Barack Obama on Monday nominated Republican Chuck Hagel as secretary of defense, and current White House counterterrorism adviser John Brennan as director of the Central Intelligence Agency.

In a press conference announcing the news, Obama said he is looking forward to working with both men, whom he described as “outstanding.” The president also said he hopes the Senate will “promptly” act on the nominations.

Obama said Hagel is “the leader that our troops deserve, adding “when it comes to national security, we don’t want to leave a lot of gaps. So we want to get moving on this.”

If confirmed, Hagel, 66, will take over from soon-to-be-retired Leon Panetta, 74, who has said that he doesn’t want to continue in Obama’s second term. Hagel served two terms in the Senate, retired in 2009 and served with the U.S. Army in Vietnam. He has two Purple Hearts.

Despite all of his achievements, several obstacles lie ahead for Hagel, who is expected to undergo a tough confirmation process with resistance mounted by Republicans who say he is anti-Israel and have issues with Hagel’s past stance on Iraq and Iran. (He was against war with the former and toughened sanctions on the latter.)

Brennan, 57, will replace Gen. David Petraeus, who left the CIA post in November because of an extramarital affair. Brennan has been working as an adviser for counterterrorism and homeland security in the Obama administration since 2009.

Mike Rogers, chairman of the House's Permanent Select Committee on Intelligence, issued a statement congratulating Brennan, noting he looks forward to working with him.