The spokesman, Jesuit Father Federico Lombardi, said Pope Benedict would arrive at the Vatican in the early evening by helicopter, "weather permitting."

Pope Benedict has been living at the papal summer villa in Castel Gandolfo, south of Rome, since Feb. 28, the date his resignation took effect. Pope Francis traveled to the villa March 23 to talk, pray and eat lunch with the retired pope.

Father Lombardi said a group of Vatican officials would welcome Pope Benedict at the Vatican helipad, but he would not specify further.

Pope Benedict will live in the remodeled Mater Ecclesiae Monastery with Archbishop Georg Ganswein, his secretary, who also serves Pope Francis as prefect of the papal household; and with four laywomen who are consecrated members of the Memores Domini group, Father Lombardi said.

Serving as a residence for a retired pope is only the latest use of the building. A small portion of the current building had been a gardener's house. In 1960, it became the headquarters of a Vatican archaeological research institute, then was used for a time by Vatican Radio.

Pope John Paul II had the building expanded to about 4,300 square feet and in 1994 established it as a monastery for contemplative nuns. For 19 years, different contemplative orders took turns living in the monastery with a mission focused on praying for the pope and the church.