During his in-flight press conference from Manila to Rome, Pope Francis confirmed he plans stops in Philadelphia, New York City and Washington D.C. during his visit to the United States this autumn.

"The three cities are Philadelphia for the meeting of families, New York … for the visit to the UN, and Washington. It is these three," the Pope told journalists during his Jan. 19 return flight to Rome from the Philippines.

Pope Francis also confirmed that his September trip will not include stops in California, the U.S. - Mexico border, or Mexico proper; there had been speculation that these sites would be added to the U.S. visit agenda, particularly after Pope Francis announced plans to canonize Blessed Junipero Serra.

The 18th century Spanish-born missionary is buried at one of the nine missions he founded in California. Many of the missions still exist on the California coast, including the Carmel Mission and Mission San Juan Capistrano.

"I would like to go to California for the canonization of Junipero, but I think there is the problem of time. It requires two more days," Pope Francis said Jan. 19.

Instead, Pope Francis will canonize Bl. Serra at the National Basilica Shrine of the Immaculate Conception in Washington D.C.

"It is a national thing," the Pope explained.

Organizers of the six-day papal trip to the United States finalized a possible itinerary last week for stops in Philadelphia, New York City, and Washington D.C.

The Holy See's permanent observer to the United Nations in New York, Archbishop Bernardito Auza is one of the organizers of the papal trip. He told CNA the trip is still in the planning stages, but Pope Francis will likely begin his trip Sept. 23 with a two-day visit to Washington, D.C.

During his time in Washington D.C., Pope Francis will canonize Bl. Serra. Other proposed events in the nation's capital including a welcoming reception at the White House, an address to a joint-session of Congress, and either a meeting with youth at a juvenile detention center or a visit to a local hospital.

Pope Francis will then travel to New York City. The Holy Father confirmed that the U.N. is on his schedule for the visit. He may address the general assembly on Sept. 25. Other proposed but unofficial stops include a visit to St. Patrick's Cathedral and Mass at the Madison Square Garden arena. Organizers have also proposed inter-ethnic and inter-religious events in New York City.

But the highlight and primary reason for the Pope's trip to the United States is the World Meeting of Families in Philadelphia.

Pope Francis will lead celebrations at the World Meeting of Families Sept. 26 and 27, the final two days of the week-long event. More than 1 million people are expected to attend a Mass on Sept. 27.

During his in-air press conference Sept. 19, Pope Francis did comment on the possibility of adding Mexico to his agenda. The Pope said that "to enter the USA from the border of Mexico would be a beautiful thing, as a sign of brotherhood and of help to the immigrants."

But now is not the time, he added.

"To go to Mexico without going to visit Our Lady (of Guadalupe) would be a drama," he laughed. "A war could break out!"

"Also it would mean three more days, and this is not clear. I think there will only be those three cities. Later there will be time to go to Mexico."