When Pope Francis touches down on American soil next week, he will be at the center of one of the largest security events in the nation's history. Michael Scotto filed this report.

Federal officials say they have received no specific credible threats in advance of Pope Francis' first visit to the United States.

That has not stopped them from putting together an elaborate security plan, however, aimed at keeping the Holy Father safe during his week-long trip.

"We fully anticipate a safe and successful visit for the Pope and for the public," says Homeland Security Secretary Jeh Johnson.

Homeland Security Secretary Jeh Johnson was in Philadelphia Friday to discuss preparations ahead of the Pope's arrival.  

Federal officials are declaring it a National Special Security Event, a designation that gives it the level of security reserved for events like the State of the Union Address and political conventions.

The result: massive street closures in New York City, Washington, D.C. and Philadelphia.

"We've worked hard to establish a perimeter that best optimizes and finds the right balance between the security for the public for the pope's visit, as well as maintaining access for the public outside the perimeter," Johnson says.

Crowds will be huge wherever the Pope goes. But none will be larger than what's expected in Philadelphia, where millions of people will be in attendance for the World Meeting of Families. 

"It is the reason Pope Francis is coming to the United States," says Philadelphia Mayor Michael Nutter.

While Security officials insist they're ready for anything—in the end, the Pope's safety may simply be in the hands of a higher power.