President Obama says he hasn't decided on a new Defense secretary, but he defended one of the names mentioned: Former Nebraska senator Chuck Hagel."I've served with Chuck Hagel," Obama told NBC's Meet The Press in an interview broadcast Dec. 30. "I know him. He is a patriot. He is somebody who has done extraordinary work both in the United States Senate (and) somebody who served this country with valor in Vietnam."Obama noted that Hagel currently serves on his foreign intelligence advisory board, and is "doing an outstanding job."Opponents have targeted the prospect of a Hagel nomination to the Pentagon, saying he has been too critical of Israel and not critical enough of Iran. This group includes some Republican senators, even though Hagel is a Republican.Some gay rights groups have also challenged Hagel, citing critical comment he made about a gay ambassadorial nominee during the Bill Clinton administration; Hagel recently apologized for the remarks.It's not known when current Defense Secretary Leon Panetta might retire. That would obviously affect the timing of an Obama nomination of a successor.Among other names being bandied about: Michele Flournoy, a former undersecretary of Defense for policy; and Ashton Carter, currently deputy secretary of Defense.On Meet the Press, Obama said: "I haven't made a decision about who to nominate. And my number one criteria will be who's going to do the best job in helping to secure America."