VATICAN CITY -

Pennsylvania's governor and Philadelphia's mayor have made their case to the Vatican for Pope Francis to visit the U.S. next year, saying his "message needs to be heard" during a massive church celebration of the family planned for Philadelphia.

Gov. Tom Corbett and Mayor Michael Nutter made their pitch Tuesday to Archbishop Vincenzo Paglia, whose Pontifical Council for the Family is helping organize the Sept. 22-27, 2015, meeting.

Both leaders presented Paglia with gifts. Nutter's was a small replica of the Liberty Bell.

Popes have attended five of the seven World Meetings of the Family, and Francis has made family issues the top priority of his pontificate, but no confirmation of his participation is expected before next year.

Nutter said the event offers Francis a "unique moment in our common history and a signature opportunity" to speak about family concerns to a huge audience.