Francis, who will turn 87 on December 17 and had part of one lung removed as a young man,, stood up briefly at the start of the event in a Vatican auditorium on Wendesday and made the sign of the cross, and then sat down.
With a soft voice, barely above a whisper, Francis told the public that "since I am not well", his reading of his speech wouldn't sound "pretty".
He then handed the printed speech to the aide while Francis remained seated on the stage.
On Tuesday, the Vatican announced that doctors had asked the pope, who has a lung inflammation causing breathing problems, to skip a three-day trip to a UN climate conference, known as COP28, in Dubai.
The trip would have begun on Friday and have seen the pontiff return to Rome on Sunday.
The Holy See's announcement of the cancelled trip also said that his medical condition had improved, but noted that the pontiff had the flu and "inflammation of the respiratory airways".
The Pope, who has made caring for the environment a priority of his papacy, wanted in some way to take part in the discussions in the United Arab Emirates, according to the Holy See.
It was unclear if Francis might read his address to the climate conference by videoconference or take part in some other form.
The Vatican said the Pope had acquiesced to the doctors' request "with great regret".
Francis was hospitalised earlier this year for three days for intravenous treatment with antibiotics of what the Vatican then said was bronchitis.
The Vatican said the pontiff in his current illness was receiving antibiotics intravenously.
In a televised appearance on Sunday, a cannula for intravenous use was visible on his right hand.
A CT scan, performed at a Rome hospital on November 25, had ruled out pneumonia, according to the Vatican.
