With thousands gathered in the Vatican to hear him speak, Pope Francis calls for a peaceful solution to the crisis in Syria.
His comments come as the United States and France consider military action against Syrian state targets in response to a deadly chemical attack last month.
"Using violence can never bring peace," he said. "War is war; violence is violence."
The pontiff also condemned the use of chemical weapons, which Western powers claim Syria deployed to kill more than 1,400 civilians in an August strike.
"In recent days, my heart has been deeply injured, by what is happening in Syria," he said. "I am anguished about the developments that are being envisaged."
Francis announced he would lead a worldwide day of prayer for Syria on Sept. 7.
