Pope Francis has created a security headache for Vatican officials because he refuses to travel in his bullet-proof Popemobile.

The 77-year-old pontiff said he was unable to properly greet people inside the custom-built “sardine can”, before remarking: “At my age I do not have much to lose”.

"I know what could happen, but it is in God's hands," he said in an interview with La Vanguardia, a Barcelona daily.

"I remember in Brazil, they'd provided for me an enclosed Popemobile, but I cannot greet the people and tell them I love them inside a sardine can, even if it is made of glass. For me it is a wall."

The Argentinian Pope had ditched the bullet-proof Popemobile in favour of open-top cars. It is a contrast to his predecessor, Benedict XVI, who often rode in the enclosed vehicle – a measure introduced after the attempted assassination of John Paul II in St Peter's Square in 1981.

Vatican officials are said to have voiced fears for his safety during his recent trip to the Holy Land, which involved public appearances in Jordan, Jerusalem and Bethlehem.