Pope Francis delivers first Angelus to Catholics worldwide NEW: Pope Francis delivers his first Angelus blessing NEW: He spontaneously walks out of Vatican territory to greet chanting well-wishers He will meet with Pope Emeritus Benedict XVI on Saturday, the Vatican says Rome (CNN) -- Thousands of Catholics waving flags from around the world packed St. Peter's Square on Sunday to hear Pope Francis deliver his inaugural Angelus. The new pontiff gave his Angelus -- or noon blessing -- from his papal apartment window. Earlier, he made the historic address after celebrating Mass at Sant'Anna Parish in Vatican City earlier. In a rare move for a pope, Francis spontaneously walked out from Vatican territory to greet cheering well-wishers outside Sant'Anna Gate. "Francesco, Francesco!" the crowd chanted. In his first week as pontiff, Francis has enjoyed global fanfare as the first Latin American pope and the first Jesuit pope in modern times. The official Mass to inaugurate Francis as the bishop of Rome -- and leader of the world's 1.2 billion Roman Catholics -- will take place Tuesday. A church 'for the poor' The new pope explained his choice of the name Francis in a meeting with journalists Saturday, and discussed how he wished for a church that was both poor and "for the poor." St. Francis of Assisi, who gave up his own wealth and prestige, is revered among Catholics for his work with the poor. Pope Francis a pontiff of firsts A blessing for all The new pope concluded the meeting with press -- which did not include questions -- with a blessing for all the journalists present and their families. Reforms to come? In just his first few days as pope, Francis has prompted speculation that he may bring in wider changes. While Francis decided the heads of the various Vatican offices will keep their jobs for now, he's not making any definitive appointments, the Vatican said Saturday. CNN Vatican analyst John Allen, who's also a correspondent for the National Catholic Reporter, said this is the first clear signal that he may be serious about reform. "It's customary for new popes to swiftly reconfirm the department heads who lose their positions when the previous pontificate ends, and then take his time about bringing in his team," Allen said. The fact that Francis has not followed that path may suggest that significant personnel moves will come sooner rather than later. Francis wants "a certain period for reflection, prayer and dialogue before [making] any definitive nomination or confirmation," the Vatican statement said. Questions about the past The Vatican has sought to quell reports over Francis' conduct during Argentina's so-called Dirty War, amid accusations that he could have done more to protect two Jesuit priests who were kidnapped. Meeting with Benedict XVI Francis will meet with his predecessor, Pope Emeritus Benedict XVI, on Saturday, the Vatican said. The meeting will take place at the papal summer residence, Castel Gandolfo, where Benedict has been staying since his historic resignation. Hada Messia reported from Rome, and Holly Yan wrote from Atlanta. CNN's Laura Smith-Spark and Karen Smith also contributed to this report.