U.S. Special Representative for North Korea Stephen Biegun has been nominated to the State Department's number two post. 

The White House said U.S. President Donald Trump on Thursday nominated the top U.S. negotiator on North Korea's nuclear weapons program as the deputy secretary of state.

The nomination comes after the current deputy secretary, John Sullivan, was picked to be the next U.S. ambassador to Russia.

Biegun will have to be approved by the Senate before assuming the new post. He is expected to retain his diplomatic activities with North Korea regardless of any new position at the U.S. State Department.