Pope Francis, who is currently hospitalized in Rome due to a severe lung infection affecting both lungs, has called upon the 1.4 billion followers of the Catholic Church around the world to pray for him as he continues his recovery.

In a written message published on Sunday, the 88-year-old pope expressed his deep gratitude for the overwhelming support he has received.

Pope Francis also extended his special thanks to his doctors at Gemelli Hospital in Rome, where he has been receiving treatment for 10 days.

"I sincerely thank the doctors and healthcare workers in this hospital for their attention to me," said Francis.

Due to his illness, Pope Francis was unable to perform the traditional Angelus prayer from the window of the Apostolic Palace before the gathered faithful in St. Peter's Square on Sunday. This has become a regular occurrence in recent weeks, as he was also absent from the prayer last week.

The Pope has been suffering from respiratory issues since before Christmas. In the hospital, doctors diagnosed him with a lung infection affecting both lungs and described his condition as "critical." At such an advanced age, pneumonia is considered extremely serious.