Admiral Timothy Keating -- commander of the U.S. Northern Command at Peterson Air Force Base in Colorado Springs may be moving on to Hawaii.
U.S. Defense Secretary Robert Gates has nominated Keating to take over as commander of the nation's Pacific Command.
In his place, one of Keating's top aids, Air Force Lieutenant General Victor Renuart Junior may take over at Northern Command.
Both nominations require Senate approval.
Northern Command began operations in 2002.
It's responsible for defending Alaska, the continental United States, Canada, Mexico and surrounding waters and for responding to natural disasters.
Its commander also oversees the North American Aerospace Defense Command -- or NORAD -- which watches for airborne threats to the United States and Canada.
Keating became commander of Northern Command in November 2004 and headed the military's response to Hurricane Katrina.
Renuart -- who is Gates' liaison to the Joint Chiefs of Staff -- is a pilot who's spent much of his military career in Europe.
As director of operations for U.S. Central Command, he oversaw planning for the 2001 invasion of Afghanistan and the 2003 invasion of Iraq.