The Vatican says Pope Francis will deliver four out of his 18 speeches in the U.S. in English, using his native Spanish for the vast majority of his homilies, greetings and other speaking engagements in his three-city U.S. tour.

Francis has polished his English during recent trips to Asia, but the Vatican spokesman, the Rev. Federico Lombardi, said Tuesday that the Argentine pope simply finds it easier to express himself in Spanish.

Francis will deliver an English speech at the White House and Congress and two greetings to U.N. staff and benefactors in Philadelphia.

Francis leaves Saturday for Cuba and arrives in the United States on Sept. 22 for a five-day visit.

Lombardi said a meeting with former Cuban leader Fidel Castro in Havana was "likely" but not scheduled yet.