The names of Deputy Defense Secretary Ashton Carter and former defense policy undersecretary Michele Flournoy are frequently floated as possible successors to Defense Secretary Leon Panetta, should he choose to step down.
According to the Washington Post, the name of Sen. John Kerry (D-Mass.) has also come up and President Obama is considering him as the next defense secretary.
Citing senior administration officials, Karen DeYoung and Greg Miller report Kerry wanted the secretary of state post, succeeding Hilary Clinton.
The Post reports U.N. Ambassador Susan Rice is the most likely candidate to take that job.
The Post is also reporting White House national security adviser Thomas Donilon, principal deputy Denis R. McDonough and Benjamin Rhodes, deputy for strategic communications, are likely to not remain in place, at least initially.