Perry, an Air Force veteran who was previously Texas’s longest-serving governor, has enjoyed a good rapport with President Donald Trump. Trump personally asked Perry if he’d take over as Homeland Security secretary, before the president asked Kirstjen Nielsen to resign earlier this month, two of the people said. Perry declined, they said.

Perry has been preparing the agency’s deputy secretary, Dan Brouillette, for the transition, two people said. It’s unclear if Trump would name Brouillette as secretary. Part of Perry’s motivation in seeking to leave before the end of Trump’s first term is a desire to build his income before retiring, two people said.

Perry, 69, was previously considered for Defense Secretary, but ultimately was tapped to lead the Department of Energy. The agency has an annual budget of around $30 billion and is responsible for work ranging from safe-guarding nuclear weapons to maintaining the Strategic Petroleum Reserve.