(CNN) - Robert Gibbs, former White House press secretary and senior adviser to the president's re-election bid, said Sunday that President Obama's nominee for defense secretary didn't perform too well during his confirmation hearing last week.
Gibbs, however, expressed confidence that former Sen. Chuck Hagel would be confirmed and would make "a good secretary of defense."
"The disconcerting thing, obviously, for anybody that watched it, was he seemed unimpressive and unprepared on the questions that, quite frankly, he knew was coming," Gibbs said on NBC's "Meet the Press."
During his testimony before the Senate Armed Services Committee, Hagel faced questions about some of his past controversial statements and positions, including his opposition to the 2007 troop surge in Iraq.
Hagel, a senator from Nebraska at the time, called the George W. Bush administration's surge proposal "the most dangerous foreign policy blunder in this country since Vietnam."
Sen. John McCain, a robust supporter of the strategy, grilled his old friend repeatedly on the topic at the confirmation hearing, asking Hagel if he was right or wrong for opposing the surge.
"Are you going to answer the question, Sen. Hagel? The question is, were you right or wrong?" McCain said. "That's a pretty straightforward question. I would like you to answer it with whether you were right or wrong and then you are free to elaborate."
Hagel didn't give a one-word answer, offering instead to try to explain his position. "I think it's far more complicated than that and as I've already said, my answer is I'll defer that judgment to history."
McCain, however, continued to demand a more succinct response.
Gibbs on Sunday said the exchange was a "vanity thing for John McCain to try to prove to a former friend that disagreed with him, that he was right on the surge and that Chuck Hagel was wrong."
But Gibbs argued none of the Iraq questions were relevant to the situations that will confront the next secretary of defense.
He pointed to Tim Geithner, who served as treasury secretary during Obama's first term, as an example of someone who faced a difficult beginning but went on to serve a largely respected tenure as secretary.
"We get into all these kerfuffles about one hearing or a few answers," Gibbs said.
"Chuck Hagel is an infantryman who's had to execute the orders of the secretary of defense and the commander in chief and understands what those people go through. And he's going to be a good secretary of defense."
- CNN's Rachel Streitfeld contributed to this report.