Pope Francis is greeted in front of United Nations headquarters by Secretary General Ban Ki-moon Friday, Sept. 25, 2015. (AP Photo/Kevin Hagen, Pool)

In this photo taken Thursday, Sept. 24, 2015, Pope Francis arrives at the JFK airport in New York from Washington, where he addressed a joint meeting of Congress on Capitol Hill. (L’Osservatore Romano/Pool Photo via AP)

In this photo taken Thursday, Sept. 24, 2015, Pope Francis is greeted as he arrives at a lunch for homeless people who are regularly fed by Catholic Charities, at St. Patrick’s Church in Washington, following his address to a joint meeting of Congress on Capitol Hill. (L’Osservatore Romano/Pool Photo via AP)

In this photo taken Thursday, Sept. 24, 2015, Pope Francis greets parishioners as he arrives at St. Patrick’s Church in Washington, following his address to a joint meeting of Congress on Capitol Hill. (L’Osservatore Romano/Pool Photo via AP)

In this photo taken Thursday, Sept. 24, 2015, Pope Francis addresses a joint meeting of Congress on Capitol Hill in Washington, making history as the first pontiff to do so.. (L’Osservatore Romano/Pool Photo via AP)

El presidente Barack Obama y el papa Francisco caminan junto a la Columnata antes de su reunión en la Oficina Oval de la Casa Blanca el miércoles 23 de septiembre de 2015. (Foto AP/Andrew Harnik)

El presidente Barack Obama, la primera dama, Michelle Obama, y el papa Francisco, saludan a los presentes en el Patio Sur desde el Balcón Truman de la Casa Blanca en Washington el miércoles 23 de septiembre de 2015. (Foto AP/Pablo Martinez Monsivais)

El papa Francisco escucha la bienvenida del presidente Barack Obama durante la ceremonia de recepción en el Patio Sur de la Casa Blanca el miércoles 23 de septiembre de 2015 en Washington. (Foto AP/Pablo Martinez Monsivais)

Pope Francis arrives to address the 70th session of the United Nations General Assembly, Friday, Sept. 25, 2015 at United Nations headquarters. (AP Photo/Mary Altaffer)

German Chancellor Angela Merkel arrives to hear Pope Francis address the 70th session of the United Nations General Assembly, Friday, Sept. 25, 2015 at United Nations headquarters. (AP Photo/Seth Wenig)