"The chance to have Pope Francis make his first North American trip to the commonwealth is an incredible opportunity," said first lady Susan Corbett. "Philadelphia, as well as the rest of the state, has so much to offer culturally, recreationally, and historically."
The World Meeting of Families is convened every three years by the Roman Catholic church to promote traditional family and church values. The 2015 event is expected to bring hundreds of thousands of people to Philadelphia for five days of prayer, lectures, and other activities.
If Pope Francis agrees to attend, Gov. Corbett said, the event could draw more than 1 million people and $100 million in economic stimulus to Pennsylvania.
James J. Maguire, who leads the Maguire Foundation and is part of the World Meeting executive organizing committee, was optimistic the Vatican trip would be fruitful.
"We're going to meet the pope and encourage him to fulfill the previous pope's pledge to come visit Philadelphia," Maguire said as he and his wife joined a winding security line at Philadelphia International Airport.
President Obama also begins a European trip this week, including a meeting with the pope on Thursday.
The World Meeting of Families organized and paid for the Pennsylvania delegation's three-day trip to Rome. Nutter and Corbett are honorary co-chairs of the nonprofit, which is responsible for raising the substantial amount of money required to host the event.
Earlier Sunday, Nutter joined a panel of political commentators on NBC's Meet the Press to discuss the crisis with Russia and the fourth anniversary of the Affordable Care Act.
Host David Gregory asked Nutter whether he worried President Obama's focus on Russia would take away from his domestic agenda.
"President Obama can do many more things than one thing at a time," Nutter said. "The world is starting to come together around this particular issue. China is with us. Russia is going to be increasingly isolated in this situation."
Nutter also said most Americans "are really tired of war," and "don't necessarily want to be in this conflict."
The mayor also said he was very proud of the Affordable Care Act and spent part of Saturday at 12th and Market Streets, talking to people about the law. He said most of the people he spoke to did not have health insurance and would now be covered.