Popes do not necessarily come from a given country, but are elected from a group of Cardinals with different nationalities. Cardinals are leaders or officials of the Catholic church from around the world who are normally chosen by a sitting pope.
Cardinals normally meet for 15 to 20 days prior to election of a new pope in order to reach a consensus on what to be done. The office of the pope falls vacant when the sitting pope resigns or dies. The election of a new pope is normally referred to as the conclave and it entails the Cardinals choosing a successor to the papal seat from amongst themselves.