Updated at 11:19 a.m.

President Obama named Ashton Carter, a former No. 2 Pentagon official, as his pick to succeed Defense Secretary Chuck Hagel.

Obama described Carter today as one of the "nation's foremost national security leaders."

"He was at the table in the situation room. He was by my side navigating complex security challenges that we were confronting," Obama said. I relied on his expertise and I relied on his judgment."

Carter called the nomination an "honor and a privilege."

He said he accepted the offer because of "the seriousness of the strategic challenges we face, but also the bright opportunities that exist for America if we grab hold of them."

He said, if confirmed, he will give Obama "candid" strategic and military advice. And, in a message to the U.S. military, he said, "I pledge to keep faith with you and to serve our nation with the same unflinching dedication that you demonstrate every day."

Carter's name began to surface this week as a possible replacement for Hagel, who announced Nov. 24 that he would step down once a successor is confirmed. NPR's Eyder Peralta noted that Carter, though unknown to the public, is "regarded as having a great intellect."

He is expected to enjoy bipartisan support during the nominating process.

Sen. Jim Inhofe, R-Okla., said earlier this week that he supports Carter "very strongly."

If confirmed, Carter will be Obama's fourth defense secretary (after Robert Gates, Leon Panetta and Hagel).

A Rhodes scholar, Carter has a doctoral degree in theoretical physics from Oxford University. He would inherit the Pentagon as the U.S. faces many global challenges, including the fight against the Islamic State militant group in Iraq and Syria, a resurgent Russia and unrest in other parts of the world. He also faces newer challenges such as cyberthreats.
Copyright 2014 NPR. To see more, visit http://www.npr.org/.

President Obama is likely to nominate Ashton Carter as his next secretary of defense, CNN, The Associated Press, The Washington Post and The New York Times are reporting.Carter served as the No. 2 defense official under Leon Panetta, and while he's relatively unknown to the public, he's regarded as having a great intellect.NPR has not independently confirmed Carter's nomination.In a profile, the AP reports that Carter "has bachelor's degrees in physics and medieval history from Yale University and received his doctorate in theoretical physics from Oxford University, where he was a Rhodes scholar."The news service continues: "He has served on the advisory boards of MIT's Lincoln Laboratories and the Draper Laboratory. He has extensive knowledge of the inner workings of the U.S. nuclear arsenal. "Carter's academic record is such that Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, jokingly noted at Carter's farewell ceremony that he has been called an 'uber-wonk' and that in Hollywood circles he would be considered 'not hot.' But Dempsey said Carter had earned respect far and wide."The New York Times notes that Carter is really the last name left on a shortlist that's been floated out by news organizations after the ouster of Secretary of Defense Chuck Hagel."President Obama, the official said, is leaning toward nominating Mr. Carter, barring last-minute complications, though he has not made a final decision," the Times reports. "With two other prominent candidates for the post withdrawing their names, Mr. Carter is essentially the last man standing."The AP reports that Sen. Jim Inhofe, a Republican from Oklahoma, said the Obama administration told him of the decision today and he supports the choice "very strongly."Update at 1:15 p.m. ET. Inhofe Clears Up Statement: The AP added this to its story on Carter: "An aide of Inhofe said later the senator had based his comments on press reports. " 'I support it very strongly,' Inhofe said of Carter's probable nomination. 'I'm very pleased he is going to be our secretary of defense. I can't imagine that he's going to have opposition to his confirmation.' " Copyright 2014 NPR. To see more, visit http://www.npr.org/.