WASHINGTON – Digging in for a fight, President Obama riled Senate Republicans and some Democrats on Monday by nominating former senator and combat veteran Chuck Hagel to lead the Pentagon and anti-terrorism chief John Brennan as the next director of the Central Intelligence Agency.

Hagel and Brennan, in separate Senate confirmation hearings, will face sharp questions on a range of contentious issues, including U.S. policy about Israel and Iran, targeted drone attacks and harsh interrogation tactics. Of the two men, Hagel is expected to face a tougher path, though both are likely to be confirmed.

Maine’s two U.S. senators, Republican Susan Collins and independent Angus King, both serve on committees that will hold confirmation hearings on the two nominees. Collins and King did not indicate a position on either Hagel or Brennan in statements released by their offices Monday, although Collins expressed concerns about some of Hagel’s past remarks.

“I know Sen. Hagel well from having served with him in the Senate. He is a friend of mine,” Collins said. “I do have some concerns with some of his statements on Iran, Hamas, and Israel. I’m sure that those issues will be explored in his confirmation hearing. As always, I will reserve judgment until that hearing is complete.”

Collins said she has worked closely with Brennan on cybersecurity and other issues, noting that she has known the nominee since he headed what is now the National Counterterrorism Center. But she, again, said she will “reserve judgment” on his nomination. Collins serves on the Senate Intelligence Committee, which will review Brennan’s nomination.

“I look forward to meeting with Mr. Brennan and questioning him about several controversial issues related to the CIA, including the increasingly paramilitary activities of the spy agency, such as the use of armed drones,” she said.

King, an independent who is caucusing with the Democrats, will have an opportunity to participate in the confirmation hearings for both men.

“Sen. Hagel and Mr. Brennan both have distinguished records of public service, and as a member of the Armed Services Committee and the Select Committee on Intelligence, I look forward to thoroughly reviewing their records and hearing their respective testimonies during the confirmation process,” King said. “I will make decisions on these nominations at the conclusion of the committee processes.”

With respect to presidential nominations, however, King said he believes the chief executive “should have significant latitude in appointing members of his own Cabinet and that executive branch candidates deserve the opportunity to have their qualifications fully and fairly evaluated.”

Hagel would be the first enlisted soldier and first Vietnam veteran to head the Pentagon.

“These two leaders have dedicated their lives to protecting our country,” Obama said, standing alongside them and the men they would succeed during a ceremony in the White House East Room. “I urge the Senate to confirm them as soon as possible so we can keep our nation secure and the American people safe.”

For Obama, a pair of combative confirmation hearings could turn into a distraction as he opens his second term. But the president signaled he was ready to take that risk.

Hagel, a former Republican senator from Nebraska, has been criticized as hostile toward Israel and soft on Iran. Opponents also have highlighted his 1998 comments about an ambassador nominee whom he called “openly, aggressively gay” — a comment for which he recently apologized.

Brennan, a 25-year CIA veteran, was under consideration to run the agency after Obama won the 2008 election but withdrew his name amid criticism from liberal activists who questioned his connection to the harsh interrogation techniques used by the CIA during the George W. Bush administration.

One of Hagel’s toughest critics, Sen. Lindsay Graham, R-S.C., called his former colleague’s foreign policy views “outside the mainstream” and said he would be “the most antagonistic secretary of defense toward the state of Israel in our nation’s history.”

Perhaps even more concerning for Hagel’s prospects has been the tepid response from some Democrats. Sen. Chuck Schumer of New York said Hagel had earned the right to a full and fair confirmation hearing, but he reserved judgment on whether he would back him. And Maryland’s Democratic Sen. Ben Cardin said he and other lawmakers “have questions that have to be answered” specifically on Hagel’s views on Iran and Israel.

Obama called Hagel “the leader our troops deserve” and someone who could make “tough fiscal choices” in a time of increasing austerity. The Pentagon is facing the potential of deep budget cuts in the coming months.

Hagel has criticized discussion of a military strike by either the United States or Israel against Iran. During his tenure in the Senate, he voted against unilateral economic sanctions on Tehran, although he supports the joint international penalties Obama also prefers. Hagel also irritated some Israel backers with his reference to the “Jewish lobby” in the United States.

The White House focused instead Monday on the military record of Hagel, who was awarded two Purple Hearts.

“Chuck knows that war is not an abstraction,” Obama said. “He understands that sending young Americans to fight and bleed in the dirt and mud, that’s something we only do when it’s absolutely necessary.”

The president, who prefers to keep a tight inner circle, has close ties to both Hagel and Brennan.

Obama and Hagel served together in the Senate and made several trips overseas. Brennan has become one of the president’s most trusted advisers, working with him during the planning of the raid that led to the death of Sept. 11 mastermind Osama bin Laden.