Marine Corps General John Kelly on Monday assumed command of the US Southern Command, which is responsible for all US military activities in Latin America and the Caribbean.
Kelly, who served as Defense Secretary Leon Panetta's senior military adviser, led a Marine task force during the US invasion of Iraq in 2003 and later commanded all US forces in western Iraq in 2008-2009.
His son, 1st Lieutenant Robert Kelley, was killed in Afghanistan in 2010 while leading a patrol.
Kelly replaced Air Force General Douglas Fraser, who is retiring.
The Miami-based command handles US military relations with Latin American countries, including counter-drug and counter-insurgency programs, and also has responsibility for the US prison for "war on terror" suspects at Guantanamo Bay, Cuba.