Marine Corps Gen. Kenneth "Frank" McKenzie has taken charge of U.S. Central command, which oversees military operations in the Middle East, central and southwest Asia.Speaking at the change of command ceremony Thursday at MacDill Air Force Base in Tampa, Fla., McKenzie said his command "remains at the ready to do what has to be done" as the U.S. wraps up counter-Islamic State operations in Iraq and Syria, and continues efforts to pressure the Taliban in Afghanistan. McKenzie took command from Army Gen. Joseph Votel, who has led U.S. Central Command since March 30, 2016.Votel praised U.S. and international efforts in the region and military leaders from other nations attending the ceremony."Because of us, a once-defeated and retreating Iraqi army has risen like a phoenix from the ashes of 2014 and now proudly defends their country," he said.Islamic State's control of Iraq and Syria peaked in 2014. International forces announced the defeat of the group last week after retaking its final stronghold in eastern Syria."We can never allow extremists to use this area as a platform to attack our homeland," and "we must safeguard access to the critical waterways that support global commerce and freedom of navigation," Votel said.Votel also addressed the ongoing fight in Afghanistan, praising Afghan and international partners for creating "the military pressure that has brought the Taliban to the table and provided us a real path to a negotiated settlement to this long war."While Afghan security forces are leading the fight against extremists in Afghanistan, the U.S. military has been fighting in Afghanistan in varying capacities for nearly two decades, a fact the U.S. president has strongly criticized."As our president said recently, great nations don't fight forever wars, and we shouldn't. It is time to bring these conflicts to a conclusion," Votel said. "This won't be as quick as anyone would like, but it can be done."There are about 14,000 U.S. troops based in the war-torn nation.Prior to taking command of CENTCOM, McKenzie served as the director of the Joint Chiefs of Staff. A career infantry officer, he graduated from The Citadel in 1979.His career includes deployments to Afghanistan in 2004 and Iraq in 2005 and 2006.