When the world learned of Pope Francis' death on Monday morning, a cardinal with longstanding ties to the US was the one to break the news.

After announcing that the pope had "returned to the home of the Father", Irish-American Cardinal Kevin Farrell took on one of his biggest roles yet: the "camerlengo", or the person who runs the Vatican after the death or resignation of a pope.

Pope Francis nominated the cardinal for the role in 2019. The cardinal will remain in the position during the "Apostolica Sedes Vacans", the period between the death or resignation of a pope until the election of the next pontiff.

He also will play an important role in the centuries-old ceremonies to mourn Pope Francis.