Pope Francis on Sunday urged the international community to seek a negotiated solution to the conflict in Syria and announced he would lead a worldwide day of prayer for peace in the country on September 7.

Francis condemned the use of chemical weapons, blamed by Western powers on Syrian government forces, but added: "war, never again". The United States and France are considering military action against Damascus in response to the chemical attack.

The pope asked the 1.2 billion Roman Catholics around the world to pray for peace in Syria on September 7 and said he would lead a special service at the Vatican.

He invited other Christians, members of other religions and all "people of good will" to join the Catholic initiative on September 7 in any way they saw fit.