Pope Francis is set to make a stop in Cuba ahead of his September trip to the United States, says the Vatican.

Father Federico Lombardi, director of the Holy See press office, made the announcement to journalists April 22.

Lombardi did not reveal any details of the visit to the Caribbean nation that is undergoing a thaw with its neighbour, the United States.

"I am able to confirm that the Holy Father Francis, having received and accepted the invitation from the civil authorities and bishops of Cuba, has decided to pay a visit to the island before his arrival in the United States for the trip announced some time ago," said Lombardi.

The Argentine pope's visit may increase Holy See ties with Cuba, which as a communist nation had not allowed full freedom of religion and expression to exist.

It could be seen as a sign of the papal effort to help normalize relations between Cuba and the United States, the Catholic News Agency reported.

Shortly before the Dec. 17 announcement of the normalization of the diplomatic relations between Cuba and the United States, former Vatican Secretary of State Cardinal Tarcisio Bertone traveled to Cuba for a private visit.

Francis played a key role in brokering a deal to open relations between the United States and Cuba after more than half a century of hostility President Barack Obama making the announcement.

He thanked the Pope for his role in opening up of Washington's relations with Havana and the release of U.S. citizen Alan Gross from Cuban custody.

"His Holiness Pope Francis issued a personal appeal to me and to Cuba's president, Raúl Castro, urging us to resolve Alan's case and to address Cuba's interests in the release of three Cuban agents, who've been jailed in the United States for over 15 years," Obama said.