“This morning Pope Francis presented with an asthmatic respiratory crisis of prolonged magnitude, which also required the application of oxygen at high flows,” the Vatican wrote about the ailing pontiff, who is being treated for pneumonia.

While Francis “continues to be alert and spent the day in an armchair,” he is “in more pain than yesterday,” it added.

He also received blood transfusions to treat anemia, according to the statement.

Earlier on Saturday, the Vatican said he would remain in hospital following his pneumonia diagnosis and will not deliver the weekly Angelus prayer – for only the third time in his almost 12-year papacy.

The pope’s condition had seemed more promising earlier in the week, with the Vatican describing him as responding “positively” to medical treatment for pneumonia on Thursday.