The Chicago-born pope addressed a crowd of 30,000 in a live-streamed message from the Vatican: "Build up community [and] friendship as brothers and sisters."

The pope urged Catholic faithful to be a "light of hope," to serve others, and to make the world a better place.

Chicago celebrates first American Pope, Leo XIV, at a sold-out Mass led by Cardinal Cupich, with local officials recommending public transport due to crowds.