President Obama on Monday nominated former Nebraska senator Chuck Hagel as defense secretary and counterterrorism adviser John O. Brennan as director of the Central Intelligence Agency.

Appearing with the two men in the East Room of the White House, Obama called Hagel “the leader that our troops deserve” and a “champion of our troops and our veterans and our military families.” He said Hagel, a former Army sergeant, would be the first person of enlisted rank and the first Vietnam War veteran to head the Defense Department.

“Maybe most importantly, Chuck knows that war is not an abstraction, Obama said.

In Brennan, Obama said, the CIA “will have the leadership of one of our nation’s most skilled and respected intelligence professionals.”

Standing alongside the nominees were outgoing Defense Secretary Leon E. Panetta and acting CIA director Michael J. Morell.

The Washington Post’s Al Kamen of In the Loop looks at the transition of Obama’s second term. (The Washington Post)

“I hope that the Senate will act on these confirmations promptly,” Obama said. “When it comes to national security, we don’t like to leave a lot of gaps between the time that one set of leaders transitions out and another transitions in. So we need to get moving quickly on this.”

In a brief speech accepting his nomination, Hagel pledged to work to “strengthen our country and strengthen our country’s alliances, and advance global freedom, decency and humanity as we help build a better world for all mankind.” He said he would always give Obama “my honest and most informed counsel.”

Brennan, who described himself as “neither a Republican nor a Democrat,” said he would “make it my mission to ensure that the CIA has the tools it needs to keep our nation safe, and that its work always reflects the liberties, the freedoms and the values that we hold so dear.”

If confirmed by the Senate, the nomination of Hagel would add a well-known Republican to the president’s second-term Cabinet at a time when he is looking to better bridge the partisan divide, particularly after a bitter election campaign. But the selection has drawn sharp criticism, particularly from Republicans, who have questioned Hagel’s commitment to Israel’s security.

While noting that Hagel “served our nation with honor in Vietnam,” Sen. John McCain (R-Ariz.) said in a statement: “I have serious concerns about positions Senator Hagel has taken on a range of critical national security issues in recent years, which we will fully consider in the course of his confirmation process before the Senate Armed Services Committee.”

McCain also said he has “many questions and concerns” about Brennan’s nomination, “especially what role he played in the so-called enhanced interrogation programs while serving at the CIA during the last administration, as well as his public defense of those programs.”

House Majority Leader Eric Cantor (R-Va.) strongly denounced the nomination of Hagel, calling him “the wrong man for the job at such a pivotal time.” The second-ranking House Republican said Hagel’s “views and inflammatory statements about Israel are well outside the mainstream and raise well-founded doubts that he can be trusted to manage the special relationship the United States shares with our greatest Middle East ally.”

Cantor also charged that Hagel’s “reported views” on Iraq, Afghanistan, Syria, Iran and defense spending “represent a call for a broad retreat” from America’s preeminent role in the world.

But former defense secretary Robert M. Gates, a Republican holdover from the George W. Bush administration who served as Obama’s first Pentagon chief, praised Hagel.

“While there are issues on which I have disagreed with him, such as the 2007 surge in Iraq, he is a man of complete integrity and deep patriotism,” Gates said in a statement. “He is also the president’s choice. The country and our men and women in uniform would be well-served by his swift confirmation.”

In an interview published Monday by the Lincoln Journal Star, Hagel said critics have “completely distorted” his record, and he denied that he is “anti-Israeli.” He vowed to set straight a record that he said would show “unequivocal, total support for Israel” and endorsement of tough international economic sanctions against Iran, the paper reported.

The choice of Hagel sets up a confirmation fight of the sort that Obama appeared unwilling to have over Susan E. Rice, his preferred pick for secretary of state. Rice pulled out of consideration for that job last month after facing sharp Republican criticism about her characterization of the September attacks in Benghazi, Libya, that killed Ambassador J. Christopher Stevens and three other Americans. Obama subsequently nominated Sen. John F. Kerry (D-Mass.) to succeed Hillary Rodham Clinton as secretary of state when she steps down.

In an appearance Sunday on CNN’s “State of the Union,” Sen. Lindsey O. Graham (R-S.C.) called Hagel’s selection an “in-your-face nomination.”

Senate Minority Leader Mitch McConnell (R-Ky.) said Hagel’s record nevertheless would be given a fair shake in the Senate. McConnell stopped short of saying whether he would support his former colleague.

“He’s certainly been outspoken in foreign policy and defense over the years,” McConnell said Sunday on ABC’s “This Week.” He added: “The question we’ll be answering, if he’s the nominee, is: Do his views make sense for that particular job? I think he ought to be given a fair hearing, like any other nominee. And he will be.”

Brennan, a veteran CIA analyst who rose to become deputy executive director during the first term of President George W. Bush, was also considered for the top CIA post in 2009, when Obama first took office. He was forced to withdraw from consideration after liberal groups accused him of complicity in the agency’s use of brutal interrogation measures under Bush — criticism that Brennan denounced as unfair and inaccurate.

His nomination now — after serving for four years as Obama’s counterterrorism adviser, a position which did not require Senate confirmation — could spur scrutiny of his role in escalating the CIA’s drone war and renew debate over the agency’s use of harsh methods.

But the level of opposition appears to have subsided. Sen. Dianne Feinstein (D-Calif.), chairman of the Senate Intelligence Committee, recently said she believes that Brennan could be confirmed.

Brennan, 57, would be filling the vacancy created by the resignation of David H. Petraeus, following the discovery that Petraeus was having an adulterous affair.

“Brennan has the full trust and confidence of the President,” an administration official said in a statement Monday. “For four years, he has seen the President every day, and been by his side for some of his toughest decisions.... Brennan is as close to President Obama as any member of his national security team.”

The nominations of Hagel and Brennan begin what White House officials have said will probably be a busy week of announcements about who will fill Obama’s second-term Cabinet and senior staff positions. The president returned Sunday from a curtailed holiday in Hawaii and must start making final personnel decisions that were delayed by the year-end negotiations with Congress over taxes and spending cuts.

Foreign policy tussle

Despite the opposition to a Hagel nomination that has arisen on Capitol Hill, a senior administration official said Sunday that the White House expects him to receive the support of Democrats, as well as many Republicans who served with him.

“Having a name floated and having one officially put forward are two different things,” the official said.

Hagel, who was twice awarded the Purple Heart for wounds suffered in Vietnam, served in the Senate for two terms, ending in 2009.

He was an outspoken and often independent voice as a member of the Senate Foreign Relations Committee, breaking with many in his party to sharply criticize the management of the Iraq war after he initially supported the U.S.-led invasion.

“A lot of Republican opposition is rooted in the fact that he left his party on Iraq,” the senior administration official said. “And we think it will be very hard for Republicans to stand up and be able to say that they oppose someone who was against a war that most Americans think was a horrible idea.”

Hagel also has been a strong advocate for veterans, an issue that Obama has spoken about frequently as tens of thousands of U.S. troops return from battlefields after more than a decade of war. The administration official said Hagel, as a result, is “uniquely qualified” to help wind down the war in Afghanistan by the end of 2014 and make budget decisions to support the returning troops.

Some of the recent criticism directed at Hagel has focused on his mixed record over the imposition of sanctions on Iran. As a senator, Hagel opposed several bills to impose unilateral sanctions on Iran. But he also supported measures to put in place sanctions as part of multinational efforts, and he endorsed labeling Iran a state sponsor of terrorism.

Hagel’s record has raised concern among some of Israel’s supporters in the United States, who fear that he may not be sufficiently committed to that country’s security.

But his defenders point to his record as a senior senator on the Foreign Relations Committee, where he voted for nearly $40 billion in military aid to Israel over his tenure.

Obama, who worked with Hagel on nuclear nonproliferation issues and other foreign policy matters in the Senate, has vowed to prevent Iran from using its uranium-enrichment program to develop a nuclear weapon.

Obama has worked to tighten both U.S. and international sanctions to pressure Iran into giving up the effort, moves that Hagel has supported in recent interviews. The Iranian government has said that it is pursuing nuclear power, not weapons.

A network of supporters

Since leaving office, Hagel has served as co-chairman of Obama’s intelligence advisory board. Hagel has advised the president to open talks with Hamas, the armed Palestinian movement that does not recognize Israel’s right to exist. He also has complained about the influence that Israel’s supporters exert on members of Congress, telling writer Aaron David Miller in an interview for his 2008 book that “the Jewish lobby intimidates a lot of people up here.”

“If Hagel is nominated, it is very difficult to imagine a circumstance in which I could support his nomination,” Sen. Ted Cruz (R-Tex.) said on “Fox News Sunday.”

But Hagel has many supporters, including former ambassadors, senators and secretaries of state who value his experience and independence.

A network of supporters has rallied in recent weeks to defend Hagel’s record as the criticism has grown. The supporters also said privately that they expect him to receive strong public backing from many Republicans and Democrats alike once the nomination is official.

Writing last week in the Wall Street Journal, Ryan C. Crocker, a former ambassador to Iraq and Afghanistan, called Hagel “a statesman,” adding that “America has few of them.”

Hagel, 66, would be taking over the Pentagon at a time of budget cuts and a changing mission after two long wars. Defense Secretary Panetta is retiring to his home in California. Hagel would become Obama’s third defense secretary; Gates, a member of the Bush administration, was retained in the post until 2011.

If confirmed, Hagel would be the second Republican in Obama’s Cabinet, after Transportation Secretary Ray LaHood.

Dan Eggen, David Nakamura, Sean Sullivan and Debbi Wilgoren contributed to this report.