On his way to Mexico, Pope Francis (L) will stop over in Havana for a historic meeting with the head of the Russian Orthodox Church, Patriarch Kirill (R)
Vatican City (AFP) - Pope Francis will meet Russian Orthodox Patriarch Kirill in Cuba next week in a historic first meeting between the heads of the two largest Christian churches, the Vatican announced Friday.
The gathering will be the first of its kind since a schism in the 11th Century split Christianity into Western and Eastern branches.
The two wings have been estranged ever since with each maintaining for centuries that they are the true heritors of the early Christian church established by the apostles of Jesus Christ.
Relations have warmed of late between Rome and other branches of the Orthodox tradition, but the Russian one, the most influential in the Eastern family, has maintained its distance, until now.
With Pope Francis having adopted an "any time, any place" approach since his 2013 election, the once-in-a-millennium sitdown has been set for Havana's Jose Marti International Airport on February 12.
Francis will stop over on his way to a scheduled visit to Mexico while Kirill is due on the communist island for the first leg of a February 11-22 trip to Latin America which will also take in Paraguay, Chile and Brazil.
A spokesman for the Russian church said the meeting would be principally focused on the persecution of Christians around the world and that a joint declaration would be issued after a private conversation between the two leaders.
- Ukraine fallout -
"The current situation in the Middle East, North and Central Africa and in several other regions where extremists are conducting a veritable genocide against Christian populations, requires urgent measures and real cooperation between Christian churches," the Moscow-based Church said in a statement.
"That is why, despite the obstacles, the decision to organise a meeting between Patriarch Kirill and Pope Francis was taken."
The meeting has been on the cards for some time with Francis having said in 2014 that he had told Kirill to just "call me and I'll come."
Relations between the two churches were framed by the bitter legacy of the Great Schism of 1054 and the recriminations, including mutual excommunications and the violence associated with the Crusades, that followed.
The Orthodox Church's refusal to accept the authority of the Roman pontiff has long been the primary barrier to reconciliation. In the Eastern tradition, all bishops are considered equal with church governance the responsibility of synods.
Culturally-rooted differences over forms of worship and observance, such as the eating of unleavened bread, contributed to the schism although many historians see it as having been primarily driven by the prevailing political forces.
More recently Vatican-Moscow relations have been strained by the fallout from the conflict in Ukraine.
Russian Orthodox officials have accused Catholics in Ukraine, who use Eastern forms of worship but are loyal to Rome, of both evangelism and fomenting Ukrainian nationalism.
There is also a festering dispute over the ownership of church properties confiscated from Eastern Rite Catholics during the reign of Soviet dictator Josef Stalin, some of which were reclaimed from the Russian Orthodox church following the fall of communism.
Since becoming Pope, Francis has met twice with Patriarch Bartholomew, an Istanbul-based cleric who is considered the ecumenical head of the Eastern Orthodox church but does not have the same ecclesiastical clout as Russia's Kirill.
The various Orthodox churches count some 260-300 million followers, with the Russian branch accounting for 165 million of them. In comparison, the Catholic church claims 1.2 billion members around the globe.
Francis has also made a priority of improving relations between Roman Catholicism and other religions.
He has defended Islam as a peaceful faith and the last month has seen him visit the main synagogue in Rome and announce plans to visit Sweden in October for a ecumenical service to mark next year's 500th anniversary of the Protestant reformation in Europe.