Cardinal Timothy Dolan said he's confident that Pope Francis is in good enough health to lead the world's 1.2 billion Catholics.

During his weekly radio show, Dolan spoke about the 76-year-old's bad knee, which gives him a slight limp.

He also said that Francis doesn't sing during mass because he only has one lung.

But Dolan said that Pope Francis seems to be healthy despite those issues.

"He's been walking all around Vatican City," Dolan said. "Until today, he's been residing at the Dome of Santa Marta, the House of Saint Martha, and has stayed there and has walked to the audiences, walked to the journalists. You were there when he had the audience with the journalists. Walked to our audience with the cardinals the other day. He likes to do that. So I think he's a man in good shape."

Francis is the ninth-oldest man elected pope.