A major bridge between Philadelphia and New Jersey and some major highways will be shut down for Pope Francis' visit the last weekend in September, and National Guardsmen will be brought in to assist with traffic control, authorities announced Wednesday.

The nearly 2-mile-long Benjamin Franklin Bridge, which crosses the Delaware River, will be closed to vehicles from 10 p.m. on Friday, Sept. 25, to about noon on Monday, Sept. 28. The bridge will remain open to pedestrians.

Mayor Michael Nutter said a 3-square-mile area extending north and south of the city center and to a portion of west Philadelphia will also be closed to all incoming traffic except emergency vehicles, starting in some areas at 6 p.m. Friday. Vehicles will be able to move around within the zone, but if they leave, they won't be able to return during the pope's weekend visit.

Transportation officials said sections of Interstates 76 and 676 and a portion of U.S. Route 1 will be closed for the weekend, starting at 10 p.m. Friday.

Interstate 95 will remain open to traffic, they said, but some ramps will be closed.

More than 1,000 state troopers are being deployed to assist in helping secure the visit.

State transportation officials said the U.S. Secret Service, responsible for the pope's security during his visit, had requested that National Guard members also help out with traffic control in the city.

The pontiff is visiting Washington and New York before making a final two-day weekend stop in Philadelphia, where the biggest public events of his U.S. trip will be held.

He'll take part in the concluding ceremony of an international gathering of Roman Catholic families and celebrate an outdoor Mass.

Both are expected to draw more than 1 million people and will be held on the Benjamin Franklin Parkway, a wide scenic boulevard that runs through the city's museum district, ending at the Philadelphia Museum of Art.