(This article was updated at 2:30p.m. Rome time with comments from Fr. Federico Lombardi)

On Friday the Vatican announced that while on his way to Mexico, Pope Francis will stop in Cuba to meet with Russian Orthodox Patriarch Kirill in the first meeting between a Pope and a leader of the Russian Orthodox Church since the Great Schism 1,000 years ago.

“The Holy See and the Patriarchate of Moscow are pleased to announce that, by the grace of God, His Holiness Pope Francis and His Holiness Patriarch Kirill of Moscow and All Russia will meet on February 12 next,” a joint Feb. 5 press release from the Vatican and the Russian Orthodox Church read.

Kirill, patriarch of Moscow and all Rus' and Primate of the Russian Orthodox Church, will arrive to Havana Feb. 11 for an official visit to South America. His Feb. 11-22 visit includes stops in Cuba, Brazil, Chile and Paraguay.

Pope Francis himself will arrive to Havana’s José Martí International Airport the next day while on his way to Mexico, where he will be on an official visit until Feb. 17.

The Pope will be greeted by both the Patriarch and Cuban president Raul Castro at the airport. From there, they will head to the presidential room of the airport, where Francis and Kirill will have a lengthy private conversation and sign a joint declaration.

In the press release, it was noted that the encounter is the fruit of “a long preparation,” and will be “the first in history and will mark an important stage in relations between the two Churches.”

While Roman Pontiffs have met with other Orthodox Church leaders, this marks the first time a Pope has met with the Russian Orthodox Patriarch since the Eastern Churches split with Rome during the Great Schism of 1054.

Both the Holy See and the Moscow Patriarchate expressed their hope that the meeting “will also be a sign of hope for all people of good will,” and invited all Christians “to pray fervently for God to bless this meeting, that it may bear good fruits.”

In a Feb. 5 press briefing on the encounter, Vatican spokesman Fr. Federico Lombardi S.J. told journalists that when Pope Francis arrives to Havana, he will be greeted with the usual protocol.   Among those present to greet the Pope when he lands will be Cuban president Raul Castro, Cardinal Kurt Koch, President of the Pontifical Council for Promoting Christian Unity, as well as the president of the Cuban bishops conference, Archbishop Dionisio García Ibáñez of Santiago de Cuba.

The private meeting between the two is expected to last “a couple of hours,” Fr. Lombardi said, noting that the time allotted for the encounter lasts from around 2:15-4:25 p.m. Afterward, they will head to a separate room to sign a joint-declaration and exchange gifts.

Two interpreters will assist in the conversation: one in Spanish, and one in Russian. The declaration, however, will be drafted in Russian and Italian.

Once the joint-declaration has been signed and the gifts exchanged, Pope Francis and Patriarch Kirill will each give short speech. The Pope will give his speech in Spanish, and the patriarch in Russian.

According to the Vatican spokesman, the speeches will not be long and complicated, but more like a “spontaneous expression of their feelings for this beautiful occasion.”

Delegations from both the Pope and the patriarch, consisting of roughly 10-15 people each, will be presented before Francis boards the plane again around 5:30p.m., bound for Mexico. Both Patriarch Kirill and Cuban President Raul Castro will see him off.

Fr. Lombardi said that while the stop in Havana has been added, Pope Francis’ trip to Mexico has otherwise not been modified, and he should stay on schedule.

Also present for the encounter in Cuba will be Hilarion Alfeyev, who currently serves as Metropolitan of Volokolamsk, is the chairman of the Department of External Church Relations and is a permanent member of the Holy Synod of the Patriarchate of Moscow.

In an interview with Corriere della Sera in June 2015, Metropolitan Hilarion hinted that a possible meeting between the Pope and Patriarch Kirill could be close. He told the agency that “such a meeting is getting closer every day, but it must be well prepared.”

Fr. Lombardi confirmed that meeting between the two was “not improvised,” but has in fact been in the works “for a long time...a couple of years.”