Pope Francis used his Christmas blessing to call for an end to fighting in Syria and the Holy Land.
The pontiff delivered his annual blessing from the Vatican on 25 December, known as Urbi et Orbi, meaning "To the City and the World". He spoke from a balcony to thousands of Catholics gathered in the square of St Peter's Basilica.
He also urged Palestinians and Israelis to abandon hate and revenge days after the United Nations security council passed a resolution condemning Israeli settlements in Palestinian territory.
He said the two countries must come together to "write a new page of history" in the midst of heightened tensions as Israeli Prime Minister Benjamin Netanyahu said he would reassess links with the UN after the vote.
He warned it had been a year where "far too much blood has been spilled" in war.
He urged the international community to "actively seek a negotiated solution" to the five-year war in Syria.
"Peace to those who have lost a person dear to them as a result of brutal acts of terrorism, which have sown fear and death into the hearts of so many countries and cities," he told some 40,000 people gathered in St. Peter's Square.
"Today this message (of peace) goes out to the ends of the earth to reach all peoples, especially those scarred by war and harsh conflicts that seem stronger than the yearning for peace," he said, speaking in Italian from the central balcony of St. Peter's Basilica.
He called for peace in Syria, urging immediate assistance to the exhausted population of the city of Aleppo, which Syrian government forces recaptured last week after four years of devastating fighting with rebels.
"It is time for weapons to be still forever (in Syria), and the international community to actively seek a negotiated solution, so that civil co-existence can be restored in the country," he said.
Francis, the first Latin American pope, also said Christmas should inspire everyone to help the less fortunate, including migrants, refugees and those swept up by social and economic upheavals.
"Peace to the peoples who suffer because of the economic ambitions of the few, because of the sheer greed and the idolatry of money, which leads to slavery," he said.
His homily comes after a Christmas Mass celebration on Christmas Eve where he said the festival had been "taken hostage" by consumerism.
"If we want to celebrate Christmas authentically, we need to contemplate this sign: the fragile simplicity of a small newborn, the meekness of where he lies, the tender affection of the swaddling clothes. God is there," the Pope said at St. Peter's Basilica.
"Jesus was born rejected by some and regarded by many others with indifference," he said.
"Today also the same indifference can exist, when Christmas becomes a feast where the protagonists are ourselves, rather than Jesus; when the lights of commerce cast the light of God into the shadows; when we are concerned for gifts, but cold toward those who are marginalized."
Additional reporting from Reuters.