WASHINGTON -- Defense Secretary Ash Carter thanked the senior noncommissioned officers he calls his "eyes and ears" with the force as he addressed the 2016 Defense Senior Enlisted Leader Council at the Pentagon Wednesday morning.

Chaired by Army Command Sgt. Maj. John Troxell, the senior enlisted advisor to the chairman of the Joint Chiefs of Staff, the council consists of the service and combatant command senior enlisted advisors. Troxell calls it "the Top 25." The council is the only time all the senior enlisted leaders get together each year.

Carter said the senior NCOs play a crucial role in conveying the concerns of the enlisted force to Defense Department leaders and serving as conduits of information from the top down. "I hope when you speak with these young men and women, you tell them how proud we are of all of them and how proud we are of what they chose to do with their lives," he said.

The secretary spent much of his time with the senior NCOs discussing readiness. Each armed service has different readiness issues, he told them, which means that no one solution will apply to all. The Army and Marine Corps are returning to full-spectrum operations after a generation of concentrating on counterinsurgency, he said. The Marine Corps has aviation issues it must address. In the Navy, shipbuilding and overhauling are affecting readiness. The Air Force is working with an air fleet that is the oldest in the service's history.

"There is a bill to be paid for 15 years of war in Iraq and Afghanistan," Carter said, but he added that he does not begrudge the money spent, noting, "If you are in, you have to be all the way in."

Nevertheless, there are costs and the Department of Defense must address those shortfalls. A new administration will need to take a serious look at the readiness issue, he said, and he believes that it will.

"The world is the world," Carter said. "So our major strategic directions will, I think, basically remain the same -- in the sense that the problems aren't going to change, but approaches to them might."

The defense secretary also spoke of the four-plus-one litany of threats -- Russia, China, Iran, North Korea and violent extremism. Those threats aren't likely to change, but events elsewhere could alter the overall equation.

The secretary specifically discussed the current efforts against the Islamic State of Iraq and the Levant. "As far as ISIL is concerned, obviously there is the complete necessity to destroy this thing," he said. "And we are going to do that."

Carter doesn't want to leave behind any vestige of the group that could potentially reconstitute the group in a couple of years. Stabilization and economic efforts have lagged behind the military campaign against the group, he said, and those lagging efforts remain a concern. Providing hope and jobs for young Arab men are keys to ensuring the ideology loses its appeal.

Overall, the military must continue to innovate and encourage agility to build the force of the future. "Generations change, kids change, societies change; it requires a constant effort," he said. "A force that has seen the future and grasps the future and gets there before anyone else does is what we need to continue to nurture."

More than any other personnel issue, Carter said, he is concerned about the geographical base of the military. The armed services need to reach into areas that are underrepresented in the armed force in order to offer every American the opportunity to serve.

The council will continue through Friday.