By Mark Abrams

PHLADELPHIA (CBS) — A top executive of the World Meeting of Families Philadelphia organization says the announcement that Pope Francis will celebrate an open-air mass in Washington, DC just days before coming to Philadelphia won’t diminish the scope and attendance at the mass here.

The Archdiocese of Washington announced Pope Francis will celebrate an outdoor mass near the Catholic University of America.

Donna Farrell, executive director of the World Meeting of Families Philadephia, says she’s not surprised by the announcement.  But she doesn’t believe it will impact the final mass the pope will celebrate in the United States — at the base of the steps of the Philadelphia Art Museum on Sunday, September 27th, to conclude the World Meeting event.

“Nothing will be like the World Meeting of Families, and it is the reason why Pope Francis is coming to the US,” she said today.  “It’s beautiful that he’s going to be able to go to Washington and to New York and, now we know, Cuba.  But in the end, Philadelphia will be the last thing that everyone remembers,” she said.

More than 1½ million are expected to come to Philadelphia for the mass on the Benjamin Franklin Parkway.

Pope Francis has also has told Philadelphia’s archbishop he wants to celebrate a mass in the Cathedral Basilica of Saints Peter and Paul, on Logan Circle, when he arrives on Saturday, September 26th.