Pope Francis has used his New Year greeting to pray for those courageously dealing with the terrorism gripping the world in "fear and bewilderment".
"The new year will be good in the measure in which each of us, with the help of God, tries to do good, day by day, that's how peace is created," he told a crowd.
Some 50,000 pilgrims, tourists and Romans gathered in St Peter's Square for his noon blessing and New Year's Day remarks.
Francis advised people to "say no to hate and violence and yes to brotherhood and reconciliation".
The Roman Catholic church dedicates the first day of the year to the theme of peace.
He also told those standing in biting cold that the new year had already begun badly.
"Unfortunately, violence has struck even on this night of well-wishes and hope," he said, referring to the attack on an Istanbul nightclub filled with New Year revellers that left 39 dead and dozens wounded.
"In sorrow, I express my closeness to the Turkish people, I pray for the numerous victims and wounded, and for all the nation in mourning," Francis said.
He prayed that God will sustain "all men of goodwill who courageously roll up their sleeves to deal with the plague of terrorism and this bloodstain which is gripping the world in a shadow of fear and bewilderment".
Earlier, during his homily during New Year's Day mass in St Peter's Basilica, Francis lamented "narcissist hearts" in societies becoming "cold and calculating".
"The loss of the ties that bind us, so typical of our fragmented and divided culture, increases this sense of orphanhood and, as a result, of great emptiness and loneliness.
"The lack of physical, and not virtual, contact is cauterising our hearts and making us lose the capacity for tenderness and wonder, for pity and compassion," Francis said.
Francis said humility and tenderness are signs of strength, not weakness.