"I was only once in Portugal many years ago, on the way to Rome, in a plane that stopped off in Lisbon," he said in an interview with Portugal's Catholic radio Renascença. "I want to go to Portugal for the centenary, but in 2017 it will also be 300 years since the discovery of the image of the Virgem Aparecida [in Brazil], so I also want to go there and promised to go there."


Francis first explicitly stated his desire to visit Fátima in 2017 at a private audience conceded to the bishop of Leiria and Fátima, António Marto, in April this year.


In the interview with Renascença, the pontiff mentioned two concerns he wanted to discuss with Portugal's bishops, relating to young people and the catechism.


"Young people are more informal, they have their own rhythm, we must let them grow and accompany them with prudence, know how to listen to them a lot," he said. "A young person is restless, they don't want to be disturbed. Sometimes they disagree, they're growing up, we need to let them grow up ... respect them and speak to them very paternally.


"It's a challenge," he concluded.

Asked how the faithful in Portugal can prepare for his visit, as only the second pope ever to come to the country, Francis said by "praying".


On Saturday Marto said that the pope's number two, the Vatican's secretary of state, Pietro Parolín, is to preside over the international pilgrimage of October 2016 at the Portuguese shrine, in order to prepare the Pope's visit the following May.