Canada Pope

Pope Francis speaks to journalists Saturday aboard the papal flight back from Canada, where he paid a six-day pastoral visit.

ABOARD THE PAPAL PLANE — Pope Francis acknowledged Saturday he can no longer travel like he used to because of his strained knee ligaments, saying his weeklong Canadian pilgrimage was “a bit of a test” that showed he needs to slow down and one day possibly retire.

Speaking to reporters while traveling home from northern Nunavut, the 85-year-old Francis stressed he hadn’t thought about resigning but said “the door is open” and there was nothing wrong with a pope stepping down.

“It’s not strange. It’s not a catastrophe. You can change the pope,” he said while sitting in an airplane wheelchair during a 45-minute news conference.