The Vatican has confirmed that Pope Francis and former Cuban president Fidel Castro held a brief meeting after Sunday Mass and the Angelus today.

Pope Francis, accompanied by a few other Vatican representatives including Apostolic Nuncio to Cuba, Archbishop Giorgio Lingua, traveled to Fidel Castro's home where the two talked about the environment and "the great problems of the contemporary world."

"Naturally, the themes of the conversation were about the dramatic themes of today and about the environment," Vatican Press secretary, Fr. Federico Lombardi told journalists in Havana Sept. 20.

The two exchanged a few books, since during his 2012 visit, Pope Benedict XVI told Castro that he would "send him some interesting books to read."

Pope Francis gave a copy of his works, "Laudato Si" and "Evangelii Gaudium" as well as a book on happiness and the spiritual life by Italian priest Fr. Alexandro Pronzato.

Most notable, however, was the collection of writings and homilies by Spanish-born Jesuit priest Fr. Amando Llorente that Pope Francis gave him. A former tutor to Castro in his youth, the priest was later exiled from Cuba in 1961 under Castro's regime.

In turn, Castro gave the Holy Father a copy of his book, "Fidel and Religion" – a synopsis of the former president's meeting with Pope-emeritus Benedict. In the front cover he wrote, "For Pope Francis, on the occasion of your fraternal visit to Cuba, with the admiration and respect of the Cuban people. Fidel."

"It's interesting, he reflects a lot on the great questions of today and tomorrow and he was interested in speaking to the Pope about this," Fr. Lombardi said of Castro. "In this sense, Laudato Si' is very important evidently because it contains the Pope's thoughts on these great themes."

Their 30 to 40 minute meeting had a casual atmosphere, Fr. Lombardi said, with Castro's wife, children and nieces and nephews in attendance.

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Alan Holdren contributed to this report.