With only a few weeks left before his inauguration, President-elect Trump is fleshing out his cabinet.

Earlier this morning, Trump announced that his pick to lead up the Department of Homeland Security was retired Marine Corps General John Kelly.

“Gen. John Kelly’s decades of military service and deep commitment to fighting the threat of terrorism inside our borders makes him the ideal choice to serve as our Secretary of the Department of Homeland Security,” Trump said in a statement.

“He is the right person to spearhead the urgent mission of stopping illegal immigration and securing our borders, streamlining TSA and improving coordination between our intelligence and law enforcement agencies. With Gen. Kelly at the helm of DHS, the American people will have a leader committed to our safety as well as one who will work hand-in-hand with America’s rank-and-file TSA, ICE and Border Patrol officers,” Trump added.

Kelly’s resume includes overseeing operations in Central and South America, as well as the Caribbean, as commander of the U.S. Southern Command.

He served 45 years with the Marine Corps, oversaw the prison in Guantanamo Bay, Cuba, and fiercely opposed President Obama’s plans to close the facility.

He served in combat in Iraq, and for a year was head of U.S. forces in the region.

Some conservative immigration groups remain wary of Kelly. Hardliners have praised him for his military experience and trust he will build a barrier along the southern border. But they worry he won’t crack down hard enough on undocumented workers.

Some Democrats have raised concerns over the number of generals the president-elect has tapped for his administration. They have cited concerns about the amount of sway the military will have in the government.

Kelly is the third of five rumored generals that Trump is said to be considering for top positions within his administration.