Pope Francis called for world peace on Sunday in a note released by the Vatican.

"I pray above all for peace. From here, war appears even more absurd," Francis, who is battling severe double pneumonia, delivered the speech in writing in place of his customary Sunday prayer with pilgrims.

When asking for prayers for the conflicts around the world, the 88-year-old pontiff specifically mentioned "Ukraine, Palestine, Israel, Lebanon, Myanmar, Sudan, and Kivu," a region in the eastern Democratic Republic of Congo.

How is Pope Francis' health?

Since mid-February, the leader of the Catholic Church has been in the Gemelli Hospital in Rome.

For the third consecutive week, the pontiff missed leading Sunday prayers at Saint Peter's Square in Vatican City.

From the hospital, the leader of the world's almost 1.4 billion Catholics expressed his gratitude in writing for the messages of support and well-wishes for his recovery.

Pope Francis spent a "calm night," the Vatican said on Sunday.

The Holy See said in its latest health update that "the pope is still resting." On Friday, the pontiff suffered an "isolated breathing crisis" and received "non-invasive, mechanical ventilation."

Francis, known to work himself to exhaustion, has continued to lead the Church from the hospital.

Since his papacy started in March 2013, this is the fourth time Francis has been hospitalized. It is also his longest absence from public view.

Edited by: Alex Berry