Pope Francis's plane prepares to land at Joint Base Andrews, Md., Sept. 22, 2015. More than one thousand people were in attendance for the pope’s arrival. (U.S Air Force photo/Airman 1st Class Philip Bryant)

Crowds cheer and applaud in anticipation of Pope Francis's at Joint Base Andrews, Md., Sept. 22, 2015. This marks the first visit by the current pope to the United States. (U.S. Air Force photo/Tech. Sgt. Robert Cloys)

President Barack Obama and his daughter, Malia Obama, prepare to greet Pope Francis as he arrives at Joint Base Andrews, Md., Sept. 22, 2015. More than one thousand people were in attendance for the pope’s arrival. (U.S. Air Force photo/Tech. Sgt. Robert Cloys)

Pope Francis waves to the crowd after arriving at Joint Base Andrews, Md., Sept. 22, 2015, after a departing Cuba earlier that day. More than one thousand people were in attendance for the pope’s arrival. (U.S. Air Force photo/Tech. Sgt. Robert Cloys)

President Barack Obama greets Pope Francis at Joint Base Andrews, Md., Sept. 22, 2015. This marks the first visit by the current pope to the United States. (U.S. Air Force photo/Tech. Sgt. Robert Cloys)

President Barack Obama greets Pope Francis at Joint Base Andrews, Md., Sept. 22, 2015. This marks the first visit by the current pope to the United States. (U.S. Air Force photo/Tech. Sgt. Robert Cloys)

Pope Francis, escorted by President Barack Obama, greets Cardinal Donald W. Wuerl (left), Archbishop of Washington, and Maj. Gen. Darryl Burke, Air Force District of Washington commander, at Joint Base Andrews, Md., Sept. 22, 2015. This marks the first visit by the current pope to the United States. (U.S. Air Force photo/Tech. Sgt. Robert Cloys)

Pope Francis is escorted down the red carpet after his arrival to Joint Base Andrews, Md., Sept. 22, 2015. More than one thousand people were in attendance for the pope’s arrival. (U.S. Air Force photo/Tech. Sgt. Robert Cloys)

Pope Francis and President Barack Obama are greeted by catholic school children at the flightline on Joint Base Andrews, Md., Sept. 22, 2015. The children are local to the National Capital Region and presented Pope Francis with a gift of flowers. (U.S. Air Force photo/Airman 1st Class Philip Bryant)

Pope Francis and President Barack Obama are greeted by catholic school children on the flightline on Joint Base Andrews, Md., Sept. 22, 2015. The children are local to the National Capital Region and presented the pope with a gift of flowers. (U.S. Air Force Photo/Tech. Sgt. Robert Cloys)

More than one thousand people look on as Pope Francis arrives at Joint Base Andrews, Md. Sept. 22, 2015. This marks his first visit to the United States. (U.S. Air Force Photo/Tech. Sgt. Robert Cloys)

Pope Francis waves as his motorcade leaves the flightline on Joint Base Andrews, Md., Sept. 22, 2015. This marks the first visit by the current pope to the United States. (U.S. Air Force photo/Airman 1st Class Philip Bryant)