President Donald Trump is nominating the Air Force general in charge of U.S. Strategic Command to be vice chairman of the Joint Chiefs of Staff.

Gen. John Hyten now serves as commander of the U.S. nuclear forces and has the lead military role for space operations. His nomination was announced Tuesday by Air Force Secretary Heather Wilson.

If confirmed by the Senate, Hyten would succeed the retiring Air Force Gen. Paul Selva.

The vice chairman is the second-ranking military officer behind the chairman but does not command troops

Trump said last December that he was nominating Army Gen. Mark Milley to succeed Marine Gen. Joseph Dunford as chairman of the Joint Chiefs. Dunford's term ends Oct. 1.