With Hillary Clinton having signalled her intention to step down as Secretary of State, names in the frame to replace her include 2004 presidential contender John Kerry, chairman of the Senate's Committee on Foreign Relations, and UN ambassador Susan Rice.
Both have experience, but some doubt whether Mr Kerry would adhere to Mr Obama's agenda. His appointment would also prompt a Senatorial election in his state of Massachusetts, which the president may wish to avoid. Ms Rice, meanwhile, was accused by Republicans in September of misleading the public after incorrectly asserting a terrorist attack on the US consulate in Benghazi stemmed from a protest.
Frontrunner to replace the Treasury secretary Timothy Geithner is the president's much-trusted chief of staff Jacob Lew.
With Defence Secretary Leon Panetta on the verge of retirement, Michele Flournoy is tipped to take over.