Pope Francis had to cancel one of his audiences on Thursday because of what the Vatican said was a "bad cold" and skipped reading prepared speeches at other meetings that went ahead.

The 86-year-old pope's Thursday appointments schedule, issued early in the morning, included audiences with three groups and four individuals.

The Vatican said he went ahead with all four of the individual audiences and two of the group audiences. At the two group audiences that were held, he did not read the prepared speeches.

The third group audience, with Italian youths, was cancelled outright, the Vatican said.

That audience had been scheduled to be the last of the day, indicating that the cold worsened in the course of the morning and that the pope was feeling too unwell to hold it.

Francis' health has been relatively good recently, apart from a persistent knee ailment that has forced him to use a cane and a wheelchair.

He was last seen in public on Wednesday afternoon when he presided at an Ash Wednesday Mass in a Rome church where he ushered in the season of Lent that leads up to Easter.

Francis marks the 10th anniversary of his election on March 13.