Trump announced a new attorney general and a new UN ambassador on Friday and told reporters "I have another one for tomorrow that I'm going to be announcing at the Army-Navy game" in Philadelphia.

"I can give you a little hint: It will have to do with the Joint Chiefs of Staff and succession," he said.

General Joseph Dunford is the current chairman of the Joint Chiefs of Staffs, made up of the heads of the Air Force, Army, Marine Corps, Navy and National Guard.

Dunford is scheduled to retire in October of next year after completing his second two-year term as chairman of the Joint Chiefs.

According to Fox News, Trump plans to name army chief of staff General Mark Milley to replace Dunford as chairman.

Milley, 60, has served in Iraq and Afghanistan and is a graduate of Princeton University.

According to several US media outlets, Defense Secretary Jim Mattis favored Air Force General David Goldfein, in keeping with a tradition of rotating the post between the services, but Trump preferred Milley.

Dunford is a Marine Corps general and there has not been an Air Force officer in the chairman's post since 2005.

The annual Army-Navy football game features cadets from the Naval Academy against their counterparts from West Point and is often attended by the president.