Mary Bruce has details on Pres. Trump's Oval Office meeting with newly-elected Canadian PM Mark Carney, who won office after campaigning against Trump's tariffs and told the president today that Canada is "not for sale"; in an ABC News exclusive, Pierre Thomas reports on the urgent FBI warning about the online network ‘764' that authorities say targets children on social media and gaming platforms and extorts them into sending violent and sexual content; ahead of the secretive conclave to elect the next pope, David Muir shares new images from inside the Vatican and reports on how this year's will be like no other; and more on tonight's broadcast of World News Tonight with David Muir.

David Muir reports on the historic moment at the Vatican - the first American pope introduced to the world - Chicago-born Cardinal Robert Prevost elected the 267th leader of the Catholic Church just 24 hours and 21 minutes after the doors closed to the Sistine Chapel, choosing the name Leo XIV; Terry Moran reports on the reactions back home from Pope Leo's brothers about his childhood in Chicago, his missionary work and why the family said they expect him speak his mind on thorny issues like immigration; Rachel Scott has details on the moving messages from Pres. Trump and former U.S. presidents' and what they believe this new American pope represents; and more on tonight's broadcast of World News Tonight with David Muir.