Pope Francis, forced to miss COP28 due to bronchitis, on Thursday urged delegates at the climate summit to "focus on the common good and the future of their children, rather than the vested interests of certain countries or businesses".
Francis, who turns 87 in December, said he was suffering from an acute form of bronchitis that had prevented him from making the trip to the summit in Dubai this weekend, on the orders of his doctor.
The pope has had a number of health problems in recent years that involved hospital stays, most recently in June. Despite his latest ailment, he is still working and meeting people.
"As you can see, I am still alive," he said in off-the-cuff remarks during an audience with people who were in Rome to attend a seminar on health and ethics.
"The doctor didn't let me go to Dubai. The reason is that it is very hot there, and you go from heat to air conditioning, and (it's not convenient) in this bronchial situation. Thank God it wasn't pneumonia. It is a very acute, infectious bronchitis," he said, according to a Vatican transcript.
Francis said he had no fever but was on antibiotics, confirming what the Vatican said in a statement on Wednesday.
During another audience on Thursday with theologians, the pope said: "Pray for me. Pray for me, not against, because this job is not easy. Thank you."
The COP28 climate summit got underway on Thursday. Francis had been due to fly in on Friday to make a speech and hold bilateral meetings before leaving on Sunday.
The pope, who has made protection of the environment one of the hallmarks of his papacy, was hoping to use the occasion to renew his calls for action against global warming.
Writing on social media platform X on Thursday, the pope urged COP28 delegates to focus on the common good, adding: "May they demonstrate the nobility of politics and not its shame."
Cardinal Secretary of State Pietro Parolin, the second-in-command at the Vatican, told reporters on Wednesday he expected to lead the Holy See's delegation at the climate talks.
(Reporting by Alvise Armellini; Editing by Janet Lawrence)