Pope Francis and Russian Orthodox Patriarch Kirill embraced and kissed on Friday, February 12 in a historic meeting, uniting to issue a global appeal for the protection of Christians under assault in the Middle East, Reuters reports.

Nearly 1,000 years after the Eastern and Western branches of Christianity split apart, the meeting at an airport terminal in Cuba was the first ever between a Roman Catholic pope and a Russian Orthodox patriarch.

"In many countries of the Middle East and North Africa whole families, villages and cities of our brothers and sisters in Christ are being completely exterminated," they said in a joint declaration in apparent reference to violence by militant groups such as Islamic State.

"Their churches are being barbarously ravaged and looted, their sacred objects profaned, their monuments destroyed." They also said large-scale humanitarian aid was required to tend to refugees fleeing Syria and Iraq, lamenting the "massive exodus of Christians."

Cuban President Raul Castro stood to the side during the ceremony, enjoying another moment in the international limelight after receiving Francis last year and restoring diplomatic relations with the United States recently, meeting President Barack Obama in Panama in April.

"If it continues this way, Cuba will be the capital of unity," Francis said.

"Now what's left is Colombia," Castro told reporters after the pope boarded his plane for Mexico, where Francis arrived on Friday evening for a five-day visit to some of the poorest and most violent corners of the country.

Dissidents in Cuba's one-party political system have remarked on the government's willingness to promote dialogue for foreigners while dismissing political opponents as mercenaries doing the bidding of the United States.