US President Barack Obama will nominate former Pentagon attorney Jeh Johnson to be the next Homeland Security chief.

Johnson is a national security expert who served as general counsel in the Department of Defense during Obama’s first term. The White House has described Johnson as a key member of the President’s counter-terrorism circle.

Johnson played a role in ending the ban on gays serving in the military and the government’s policy on the legality of drone strikes. He replaces Janet Napolitano, who stepped down from the position last month. His nomination requires Senate confirmation.