President Barack Obama will nominate former Sen. Chuck Hagel, a Nebraska Republican and Vietnam veteran, to be secretary of defense, according to a person close to the process and a senior administration official.
The White House informed the Hagel camp over the weekend that Obama intends to announce the nomination today.
Hagel, 66, would add a well-known Republican to the president's second-term Cabinet at a time when Obama, after a bitter presidential campaign, is looking to better bridge the partisan divide.
But Hagel's expected nomination has drawn sharp criticism in recent weeks, particularly from Republicans who have questioned his commitment to Israel's security.
The choice sets up a nomination fight Obama appeared unwilling to have over his preferred pick for secretary of state, Susan Rice, who pulled out of consideration for that job last month amid Republican complaints over her role in explaining the attack in Benghazi, Libya, that killed Ambassador J. Christopher Stevens and three other Americans.
In an appearance Sunday on CNN's "State of the Union," Sen. Lindsey Graham, R-S.C., called Hagel's selection "an in-your-face nomination."
But Senate Minority Leader Mitch McConnell, R-Ky., said that Hagel's record would be given a fair shake in the Senate if he is nominated. McConnell stopped short of saying whether he was prepared to support or oppose his former colleague.
"The question we'll be answering if he's the nominee is do his views make sense for that particular job," McConnell said on ABC's "This Week." "I think he ought to be given a fair hearing, like any other nominee. And he will be."
The Hagel announcement will begin what White House officials have said will likely be a busy week of announcements regarding who will fill out Obama's second-term Cabinet and senior staff.
Obama returned from a curtailed holiday in Hawaii on Sunday, and will begin making a series of final personnel decisions in the next few days.
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.
Hagel, who twice received 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 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 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 Afghanistan War by the close 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 about the imposition of sanctions on Iran. During his time in the Senate, 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 Hagel may not be sufficiently committed to Israel's security. His defenders, however, point to his record on the Senate Foreign Relations Committee, where he voted for nearly $38 billion in military aid to Israel over his tenure.
Obama, who worked with Hagel on nuclear non-proliferation 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.
Since leaving office, Hagel has served as co-chairman of Obama's intelligence advisory board. He has advised the president to open talks with the Palestinian movement Hamas. 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."
A network of supporters has rallied in recent weeks to defend Hagel's record, and they said privately that they expect him to receive strong backing once the nomination is official.
Hagel would take over the Pentagon at a time of budget cuts and a changing mission after two long wars. Defense Secretary Leon Panetta is retiring to his home in California.