Pope Francis has been put on a ventilator after suffering from two "acute respiratory insufficiency" episodes earlier today.

In an update, the Vatican confirmed that the 88-year-old was placed on a non-invasion, mechanical ventilator.

The Holy City revealed the update came after a build up of mucus in the airways of the Pope's lungs.

“Today, the Holy Father presented two episodes of acute respiratory failure, caused by significant accumulation of endobronchial mucus and consequent bronchospasm," the Vatican said.

“Two bronchoscopies were therefore performed with the need for aspiration of abundant secretions. In the afternoon, non-invasive mechanical ventilation was resumed.

“The Holy Father has always remained vigilant, oriented and collaborative. The prognosis remains reserved.”