"This brings a responsibility for each to work so that the world becomes a community of brothers who respect each other, accept each other in one's diversity, and takes care of one another," the pope said.
Setting aside his prepared text for a moment, he expressed impatience with violence in the world. "What is happening in the heart of man? What is happening in the heart of humanity?" Francis asked. "It's time to stop."
He told the crowd this reflection was inspired by letter he received from a man — "maybe one of you" — who lamented that there are "so many tragedies and wars in the world."
"I, too, believe that it will be good for us to stop ourselves in this path of violence and search for peace," Francis said.
In his remarks to the often-applauding crowd, he also expressed hope that "the gospel of brotherhood speak to every conscience and knock down the walls that impede enemies from recognizing that they are brothers."
The Catholic church dedicates Jan. 1 to the promotion of word peace.
Earlier, during his homily at New Year's Mass in St. Peter's Basilica, Francis spoke of humanity's journey in the year unfolding and invoked what he said where "words of blessing," explaining that they are "strength, courage and hope."
"Not an illusory hope," he added, "based on frail human promises, or a naive hope which presumes that the future will be better simply because it is the future."
In his first year as pope, Francis has charted a path for what he calls a "poor" church attentive to the needy. While offering new year's wishes to the crowd in the square, Francis pressed his campaign on behalf of the downtrodden.
"We are also called to see the violence and injustices present in so many parts of the world, and which cannot leave us indifferent and immobile," Francis said. "There is the need for the commitment of all to build a society that is truly more just and united."
Hearing "the cry of peace from peoples who are oppressed by war and by violence," Francis prayed that "the courage of dialogue and reconciliation prevail over the temptation for vendetta, arrogance, corruption."