Cuban President Raul Castro has promised to attend all Pope Francis’s masses when the pontiff visits Cuba, Russia Today reported.

Castro said he may even go back to praying and church if “the pope continues to talk as he does.”

The talks between the Cuban leader and the pontiff in Vatican were strictly private and lasted for about an hour.

According to Cuban and Vatican officials, Castro made a stop in the Vatican on the way back from Moscow’s V-Day celebrations to thank Pope Francis for his mediation between the US and Cuba.

"I thanked the Pope for what he did,” Castro told reporters as he left the Vatican, adding he was "really impressed by his wisdom and his modesty."

“When the pope goes to Cuba in September, I promise to go to all his masses, and with satisfaction… If the Pope continues this way, I will go back to praying and go back to the church, and I'm not joking," the Cuban leader said.