Pope Francis delivers a speech during a meeting with scholars at the Vatican on Wednesday. (Giorgio Onorati/EPA)

Pope Francis and the leader of the powerful Russian Orthodox Church will hold talks in Cuba next week, the first meeting ever between a pope and a Russian patriarch and an encounter that some experts believe may help soothe conflicts in the Middle East.

It isn’t clear what the agenda will be for the meeting between Francis and Patriarch Kirill I, the head of the largest and wealthiest branch of Orthodox Christianity. But experts predict it could be a significant step — if probably symbolic — toward mending a schism that has divided Christianity between East and West for nearly 1,000 years.

“Pope John Paul II said, ‘The church breathes with two lungs, the Eastern churches and the Western church.’ This is one of those meetings of great historic importance. It’s a good moment, and we need good moments,” said Bishop James Massa, a former longtime head of ecumenical and interreligious affairs for the U.S. Conference of Catholic Bishops.

The announcement set off debate about possible geopolitical and internal church maneuvering to explain why the meeting is happening now, after decades of overtures by the Vatican.

Some experts said Patriarch Kirill is looking to elevate his global standing ahead of a rare pan-Orthodox summit slated for June. Others saw a desire by both sides to draw closer at a time of crisis for Middle Eastern Christians.

The Russian wing is the largest of the 14 self-governing sections of the Orthodox Church. Catholicism and Orthodoxy have been formally estranged since the 11th century over issues such as papal authority and, more recently, disputes involving Roman Catholic reach into traditionally Orthodox regions.

Popes for decades have been meeting with the spiritual leaders of the Orthodox Church. However, the Russian wing has been unwilling to do something similar until now.

“I told Patriarch Kirill I, we can meet wherever you want — you call me and I’ll come,” Pope Francis told reporters on Nov. 30.

[Pope also faces rifts inside the Vatican]

For Francis, the brief summit in Havana will mark a milestone in his quest to forge closer ties among the world’s churches, a movement called ecumenism that is seen as a chief principle of his papacy.

Chad Pecknold, a theologian at Catholic University, said the pull for Francis is obvious. “Moscow has a political and ecclesial force as the largest Eastern Orthodox church in the world,” he said.

Such a meeting has eluded several popes before Francis, including John Paul II, who directly challenged the dominance of the former Soviet Union during the early years of his papacy and later failed to win a visit to Russia following the fall of communism.

“The patriarch of Russia was the prize that could not be attained,” said Daniel Philpott, a professor of political science and peace studies at the University of Notre Dame. “That was always a bridge too far for ecumenism.”

Symbolism aside, the meeting probably won’t lead anytime soon to changes in the routine faith lives of Christians. Although the Orthodox constitute the second-largest church in the world, their numbers are very small in the United States. Also, the theological divides between the faiths remain enormous, centering on the Orthodox Church’s rejection of the ultimate leadership of the pope.

“If you can’t agree on the mechanism for resolving conflict, then you can’t resolve conflict,” said George E. Demacopoulos, head of the Orthodox Christian Studies Center at Fordham University.

[Francis looks to the Middle East with concern]

The Orthodox Church has a complicated but interconnected relationship with the Russian government, and today some former communists — including Putin — work closely with the church as a way to promote Russian identity.

For this reason, the meeting will also be watched by those connected to the conflict in Syria. Russia seeks a wider mandate for its airstrike campaign in Syria, and because of the close relationship between the Orthodox Church and the Kremlin, the meeting carries risks for Pope Francis, Philpott said.

“There is a chance that Francis could seem co-opted in a sense that the Russians in both church and state are seizing the mantle of protecting Christians worldwide,” he said.

Meanwhile, Demacopoulos said the significance of the meeting for ecumenism is overstated. Kirill, he said, is motivated primarily by the upcoming pan­Orthodox synod, where he wants to be seen as a power broker.

“This is all internal [Orthodox] posturing over who speaks for Orthodoxy,” Demacopoulos said.

But Massa, the U.S. bishop, said the meeting is “good for Orthodoxy. It puts pressure on the many Orthodox jurisdictions to speak with a unified voice” to the Catholic Church.

Boorstein reported from Washington. Brian Murphy in Washington contributed to this report.

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Today’s coverage from Post correspondents around the world