The Pope is set to answer the prayers of a humble Bosnian postman and pigeon breeder.

On June 6, Pope Francis will release three of Marin Cvitkovic's white pigeons from the steps of Bosnia's presidential building in a gesture designed to spread his blessing over the troubled country and its three ethnic groups.

"Pigeons represent peace and love," Mr Cvitkovic said. "May they finally bring a normal life to everyone in my country."

During an 11-hour visit, the pontiff will hold a mass in Sarajevo aimed at boosting unity efforts in a country ravaged by war two decades ago.

When the 39-year-old Catholic heard about the trip, he immediately offered some of his 30 pigeons to help deliver Pope Francis's message.

He has been breeding pigeons in his village of Ilici, near the southern city of Mostar, since he was 10.

Delivering post all over the south of the country, Mr Cvitkovic often drives long distances and takes his birds with him. He releases them and they are back home by the time he returns.

"Breeding requires sacrifices and my wife knows that," Mr Cvitkovic said. "She is jealous of my pigeons."

Ana Cvitkovic said her husband is "a man who stands and stares for hours into the skies. Is it love or an obsession? I believe it is love".

When the pigeons return home after the pope's release some 100 kilometres away, she said "they will bring the blessing back to this house".

But what if they do not come back?

"Then they will spread the blessing throughout Bosnia-Herzegovina. May they carry love, peace, happiness and unity to our troubled country," Mr Cvitkovic replied.

This will be the third time a pontiff has visited Bosnia since the end of the 1992-95 war between Muslim Bosniaks, Christian Orthodox Serbs and Catholic Croats. The conflict took 100,000 lives and left the three groups deeply divided.