PHILADELPHIA — Pope Francis is coming to the United States.

Francis confirmed Monday that he will travel to Philadelphia next September for the World Meeting of Families, a conference held every three years in a different city to celebrate the importance of family.

Francis’ announcement, at an interreligious Vatican conference on traditional family values, ended months of lobbying and speculation.

Philadelphia Mayor Michael Nutter, Pennsylvania Gov. Tom Corbett and Philadelphia Archbishop Charles Chaput, the conference’s organizer, met with Francis at the Vatican and personally invited him to the city in March.

Vatican officials toured the city in May and President Barack Obama, U.N. Secretary-General Ban Ki-moon and Congress have extended invitations.

Just last week, more than 10,000 Philadelphia Catholic school children sent handwritten notes encouraging Francis to make the visit.

The pope is also expected to visit New York and Washington, but Vatican officials Monday would not confirm those legs of the trip.

The pope “wanted to guarantee his presence to the organizers of the World Meeting of Families in Philadelphia 2015, but for the rest I have nothing to say, no concrete information to give,” the Vatican spokesman the Rev. Federico Lombardi told reporters.

The Vatican’s envoy to the United Nations last week strongly hinted that Francis would visit New York to address world leaders at the General Assembly, saying the coming 70th anniversary of the world body would be “the ideal time.”

Archbishop Bernardito Auza, the permanent observer of the Holy See, told The Associated Press that “if he comes to Philadelphia, he will come to New York.”