Pope Benedict will see out his life in prayer, "hidden from the world", he said yesterday in his first personal comment on his plans since he stunned Catholics by announcing his retirement.

His remarks followed Monday's resignation notice which spoke of a life dedicated to prayer. The Vatican has said the 85-year-old German will live within its walls. His seclusion may allay concern the first living ex-pope in centuries might trouble Church unity.

Speaking unscripted to thousands of priests from the diocese of Rome, in what turned out to be a farewell address in his role as bishop of the Italian capital, Benedict outlined a cloistered life ahead:

"Even if I am withdrawing into prayer, I will always be close to all of you and I am sure you will be close to me, even if I remain hidden to the world," he said.

After February 28, when he becomes the first pontiff in hundreds of years to resign instead of ruling for life, Benedict will first go to the papal summer retreat at Castel Gandolfo, south of Rome, and then move into the four-storey Mater Ecclesiae convent, in the gardens behind St Peter's Basilica.

The Vatican said he will not influence the election of his successor, which will take place in a secret conclave to start between March 15 and 20.

But his unprepared comments to his priests in the Vatican was the first time the pope had spoken specifically in public about how he will spend his time after his resignation.

The Vatican said experts will have to decide what his title should be and if he will wear the white of a pope, the red of a cardinal or the black of an ordinary priest.

"In my opinion, once he resigns he should put aside the white cassock and put on the robes of a cardinal," said Father Thomas Reese, senior fellow at the Woodstock Theological Centre at Georgetown University. "He should no longer be called pope, or Benedict, or your Holiness, but should be referred to as Cardinal Joseph Ratzinger."