Celebrating Mass at a stadium in front of tens of thousands of people in a Sarajevo stadium Pope Francis has said "War never again!"

"War means children, women and the elderly in refugee camps; it means forced displacement, destroyed houses, streets and factories. Above all countless shattered lives," said Francis during his one day visit to Bosnia-Herzegovina.

"You know this well having experienced it here," the Pope said noting the 1992-95 Bosnian conflict, in which 100,000 people died and two million were displaced after the break-up of the former Yugoslavia.

Events in Sarajevo in 1914 also triggered World War One 101 years ago.

During his meeting the Pope met members of the Muslim, Orthodox Christian and Jewish communities.

Bosnia remains divided along religious and ethnic lines, 20 years after its civil war which depleted the Catholic population, the BBC reported.

Pope Francis warned that the world faces "a kind of third world war being fought piecemeal and, in the context of global communications, we sense an atmosphere of war."

After the breakup of Yugoslavia, the war killed around 100,000 combatants and civilians. The fighting split largely along ethnic lines, among the predominantly Orthodox Serbs, the predominantly Catholic Croats, and the predominantly Muslim Bosniaks.

Pope Francis' homily was given in Sarajevo's Kosevo Stadium.

He had referred to Sarajevo, with its synagogues, churches and mosques side by side, as a "European Jerusalem", a crossroads of cultures, nations and religions which required "the building of new bridges while maintaining and restoring older ones."

Twenty years ago in 1995 the signing of the Dayton Agreement ended the Bosnian War for Independence, The Telegraph reported.

"Peace is God's dream, his plan for humanity, for history, for all creation," said. However, this plan "always meets opposition from men and from the evil one."

The trip is Francis's eighth abroad in just more than two years as the leader of the world's Catholics.

Some 40 per cent of Bosnia-Herzegovina population is of Islamic heritage, just more than 30 per cent are come from the Serbian Orthodox tradition and about one in ten, mostly Croats, describe themselves as Catholics.

Pietro Parolin, the Vatican Secretary of State who heads up the Holy See's diplomacy, said a key goal of the trip would be boosting the morale of the Catholic community, The Telegraph reported.

"The consequences of war have been felt particularly by the Catholic community. In some parishes there are very few families left, many of them elderly," Parolin said.

"In December the 20th anniversary of the war will be remembered but the traces and the wounds of war are still there."