At his regular Angelus address today, the Pope made no direct reference to his health.

But he told the faithful gathered in St. Peter's Square, "My ministry is supported by the incessant prayer of the people of God: By so many people unknown to me -- but very close to my heart -- who offer to the Lord their prayers and their sacrifices according to the aims of the Pope."

"In the moments of great difficulty and suffering, this spiritual force is real help and an intimate comfort," he added from the window of his study.

The Holy Father, 82, has appeared frail in recent months. His ailments include an arthritic knee.