Army Command Sgt. Maj. John Troxell will be the next senior enlisted adviser advisor ​to the chairman of the Joint Chiefs of Staff, the Defense Department announced Wednesday.

Troxell, who will be the third noncommissioned officer to serve in that role, was selected to replace Marine Corps Sgt. Maj. Bryan Battaglia, who is retiring.

"All of the candidates epitomize senior enlisted leadership," Marine Corps Gen. Joseph Dunford, chairman of the Joint Chiefs, said in a statement. "Sergeant Major Troxell is someone soldiers, airmen, Marines and sailors can look up to. He can inspire people, and he is someone I trust to tell me things straight."

The senior enlisted adviser advisor ​to the chairman, or SEAC, is a relatively new position, created a decade ago to work alongside the military’s top officer, regularly joining the top brass for meetings in "the tank," and advising the four-star officers on joint personnel matters.

Troxell currently serves as the senior enlisted leader for United Nations Command, Combined Forces Command and U.S. Forces Korea, stationed in Yongsan, South Korea.

He enlisted in the Army in 1982 as an armored reconnaissance specialist. He has served combat tours of duty in Operations Just Cause, Desert Shield/Storm, Iraqi Freedom and Enduring Freedom.

Troxell was selected from a small pool of senior NCOs who already were serving in other top senior enlisted jobs. Under DoD policy, eligibility for the Joint Chiefs of Staff position is limited to the small group of senior enlisted advisor advisors ​assigned to the military’s top four-star commands.

As the SEAC, Troxell will serve as the military’s most senior noncommissioned officer. He will be the principal military adviser advisor ​to the chairman and defense secretary on all matters involving joint and combined total force integration, utilization, health of the force, and joint development for enlisted personnel, according to information released by DoD.

At the discretion of the JCS chairman, the duties of the SEAC may vary, but the senior NCO generally devotes considerable time to traveling throughout the Defense Department, observing education and training and communicating with the force.

The SEAC’s tour of duty typically lasts two years and runs in conjunction with the chairman’s tenure.

Army Command Sgt. Maj. William "Joe" Gainey was the first to hold the SEAC position, from October 2005 through April 2008. Battaglia assumed the job in September 2011.

During his tenure, Battaglia has traveled extensively and played a direct role in the selection of senior enlisted leaders for combatant commands and other joint assignments. He was also central to Joint Staff discussions about military retirement reform proposals that have gained support on Capitol Hill.