The pope reads his homily while celebrating high Mass at Madison Square Garden.

Pope Francis raises his chalice as he celebrates Mass at Madison Square Garden.

Pope Francis is shown on three large video monitors to the crowd of 18,000 at Madison Square Garden.

Pope Francis arrives to celebrate Mass at Madison Square Garden on Friday evening.

Thousands of people make their way in slow-moving lines on the western edge of New York’s Central Park, waiting to get in to see Pope Francis’ procession through the park.

People line the sidewalk on Third Avenue in New York waiting for Pope Francis to arrive for a visit to Our Lady Queen of Angels School.

Fans of the pope raise their cameras and cellphones as his motorcade and popemobile approaches during a motorcade through Central Park on Friday.

Pope Francis passes members of the Young People's Chorus of New York City as he leaves a multi-religious gathering at the National September 11 Memorial Museum.

At the National September 11 Memorial & Museum, former New York City Mayor Michael Bloomberg shows the pope a fragment of a New Testament Bible that was found in debris of the South Tower of the World Trade Center.

Pope Francis attends a multi-religious service at the 9/11 Museum behind a massive steel column, damaged during the attacks of Sept. 11, 2001 in New York. Following the attacks the column was covered with photos and graffiti to remember lives lost.

Pope Francis shakes hands with a New York City officer while visiting the 9/11 Memorial plaza on Friday in New York.

Former New York Mayor Michael Bloomberg, left, Pope Francis, and Cardinal Timothy Dolan look at a segment of the radio and television antenna that was damaged in the attacks of Sept. 11, 2001, while visiting the 9/11 Museum in New York.

Pope Francis, second left, reads a passage during a multi-religious service at the 9/11 Museum in New York City. The Pope is on a two-day visit to New York which includes addressing the United Nations and holding mass at Madison Square Garden before heading to Philadelphia.

Pope Francis prays at the edge of the South Pool at the World Trade Center in New York.

Pope Francis addresses the 70th session of the United Nations General Assembly Friday at United Nations headquarters.

Pope Francis, center, arrives to address the 70th session of the United Nations General Assembly.

Pope Francis touches a student's head as he visits Our Lady Queen of Angels School, accompanied by Joanne Walsh, left, the school's principal, in East Harlem in New York, Friday, Sept. 25, 2015. (Tony Gentile/Pool Photo via AP)

The pope delivers his speech at Our Lady Queen of Angels School in East Harlem in New York on Friday.