President Barack Obama will take questions from reporters Friday, the White House said, as US policy on Syria faces new challenges from an assertive Russia.
Obama will make a cabinet nomination announcement at 1930 GMT, and will then take questions from the press, the White House said.
The cabinet change involves the appointment of a new secretary of education.
Obama will go before the press just two days after Russia, an ally of Syrian President Bashar al-Assad, started launching air strikes against what it says are the Islamic State group and other "terrorist" elements.
The United States has expressed doubt over what the targets really are and suggested they might be rebel soldiers fighting to oust Assad, a goal that Washington supports.