Pope Francis will visit Cuba before flying on to the United States for his visit there in September, the Vatican said.

The stop in Cuba during a trip that will include visits to the White House, Congress and the United Nations will underline the role the Vatican played in helping restore diplomatic relations between Havana and Washington that had been frozen for more than half a century.

Vatican spokesman Father Federico Lombardi did not specify how long the stop in Cuba would last, saying only that Francis had accepted invitations made by the Cuban government and the Cuban Roman Catholic Church.

The pope is due to arrive in Washington on September 22 and will also visit New York and Philadelphia.

It will be the Argentine pope's first visit to Cuba as pontiff. Both his predecessors, John Paul II and former Pope Benedict XVI, visited the island and met Cuba's revolutionary leader Fidel Castro.