Pope Francis suffered two episodes of "acute respiratory insufficiency" on Monday as the 88-year-old pontiff continues to battle pneumonia, according to Vatican News, citing the Holy See Press Office.

Pope Francis is alert after suffering two episodes of "acute respiratory failure" on Monday afternoon, the Vatican has said. Doctors were forced to intervene to clear mucus from the Pope's lungs, an update from the Holy See said, though it said he was alert throughout.

Pope Francis experienced two respiratory episodes Monday caused by a buildup of mucus, another setback for the Catholic Church leader as he nears his third week of hospitalization. The Holy See Press Office said the breathing setbacks were created by a buildup of mucus in the pope’s lungs and a bronchial spasm (a sudden tightening of airway muscles making breathing difficult).