Pope Francis is expected to remain hospitalized after he was newly diagnosed with a respiratory tract infection.

The pontiff has been in a hospital in Rome since Friday last week to undergo diagnostic tests and receive treatment for bronchitis.

The Vatican on Monday said the results of the tests showed that he has a "polymicrobial infection of the respiratory tract, which has led to a further change in therapy." It said the symptoms "require appropriate hospital treatment."

It's unclear how long the pontiff will be hospitalized. The Vatican said on Monday night that Francis is in stable condition, with no fever.

Francis began complaining of poor health early this month. He said he caught a "strong" cold and asked his collaborators to read his prepared remarks at the last two weekly General Audiences.

Concerns are growing about the health of the 88-year-old pontiff. He was admitted to hospital for respiratory problems in March 2023.