Pope Francis

And he's carrying some heavy burdens.

There's the threat from Islamic State militants in Iraq and Syria, and the Syrian civil war and refugee crisis. Also, Russia's moves in Ukraine and, more recently, in Syria.

On Monday evening, Obama and Russian President Vladimir Putin (POO'-tihn) meet on the sidelines of the U.N. gathering. It will be their first face-to-face encounter in nearly a year.

This journey is expected to be  most centered on ordinary Catholics: a Vatican-organized rally for the family that will culminate in an outdoor Mass for a million people.

Francis will spend the last two of his six days in the U.S. in Philadelphia as the star attraction at the World Meeting of Families, a conference for more than 18,000 people from around the world that has been underway as the pope traveled to Washington and New York.

The Pope then paid tribute to the victims of 9/11 with a prayer service at ground zero.

Francis' agenda for his first full day in New York was packed with contrasts befitting a head of state dubbed the "slum pope."

Francis' agenda reflected both his global stature and his of-the-people approach, taking him from the solemnity of ground zero to the struggles of East Harlem.

His visit was scheduled to include events as large as a processional drive through Central Park, as personal as meetings with schoolchildren and immigrants, and as inspiring for the faithful as Mass for thousands at Madison Square Garden.

The ceremony for the Chinese leader looks similar to the one the White House held Wednesday for Pope Francis, but with a few notable exceptions.

When the pontiff called on Congress to take "courageous action" on climate change, he also talked about the role he sees for technology in the world, quoting a papal encyclical published earlier this year.

“We have the freedom needed to limit and direct technology,” Francis said, “to devise intelligent ways of developing and limiting our power, and to put technology at the service of another type of progress, one which is healthier, more human, more social, more integral."

Francis made a last round of greetings and selfies with Washington-area students, pausing to pat a little girl's face and touch boys' heads as he made his way to the black Fiat carrying him to Andrews Air Force Base.

He will fly to Kennedy Airport, where his greeting party includes Cardinal Timothy Dolan and 200 indigent people.

Francis' plans Thursday evening include a motorcade along Fifth Avenue and a vespers service at St. Patrick's Cathedral.

It has been the trip of a lifetime for Catire Walker and Noel Zemborain, who quit their respective jobs in food service and marketing to lead their four children on an unforgettable tour of the Americas.

Their destination: The World Meeting of Families in Philadelphia, a Vatican-sponsored conference designed to strengthen family bonds. Pope Francis will close the event at a Saturday night festival and celebrate a public Mass the following day.

Referencing the migration crisis in Europe as well as the United States' own struggle with immigration from Latin America, Francis summoned lawmakers "to respond in a way which is always humane, just and fraternal."

"We must not be taken aback by their numbers, but rather view them as persons, seeing their faces and listening to their stories, trying to respond as best as we can to their situation," Francis urged.

Clutching a yellow T-shirt and a note about immigration, she was someplace she wasn't supposed to be. The uniformed security officer and another in a suit coming toward her probably seemed intimidating. It wasn't until Francis himself motioned to her that she relented and let a security agent carry her to side of the open-air Jeep.

Standing in the popemobile, the pope did what this pope so often does: He gave her a hug and kiss. And Cruz made sure she stuck around long enough to give the pope the shirt and her message.