Pope Francis rides in an open vehicle to greet the faithful as he arrives to celebrate an open air Holy Mass at The National Shrine in Sastin-Straze, some 70 km north of Slovakian capital Bratislava on Wednesday. Photo: AFP

Pope Francis on Saturday blamed the EU's nationalist divisions for a lack of coordination on migration as he began a landmark trip to Greece, aiming to improve complicated relations with the country's Orthodox Church.

Francis said that Europe was "torn by nationalist egoism" on migration during a meeting with EU vice president Margaritis Schinas, Greek President Katerina Sakellaropoulou and Prime Minister Kyriakos Mitsotakis, among other officials.

The European community "continues to temporize" and "appears at times blocked and uncoordinated" instead of being an "engine of solidarity" on migration, the pope said.

The 84-year-old's visit to the Greek capital is the first by a pope since John Paul II in 2001, which in turn was the first papal visit to Athens since the 1054 Schism between the Catholic and Orthodox Churches.

Meeting with the head of the Orthodox Church of Greece, Archbishop Ieronymos II, Francis stressed the "common roots" of the two churches and followed John Paul in asking for forgiveness "for the mistakes committed by many Catholics."

Speaking to members of Greece's small Catholic community, which represent just 1.2 percent of the majority-Orthodox population, Francis urged them not to lose faith.

Francis has long championed refugees, and on Sunday will return to the island of Lesbos, which he last visited in 2016 during the early years of the migration crisis. 

Flying in after a two-day trip to Cyprus, the pope landed shortly after 0900 GMT in the Greek capital, where security was heightened over expected protests by Orthodox hardliners among whom anti-papal sentiment remains strong.

Up to 2,000 police are deployed in Athens to monitor possible disruptions by Orthodox hardliners, who blame the Catholics for the Schism and the 1204 sacking of Constantinople during the Fourth Crusade.

Reciprocal excommunications exchanged between the two churches after the Schism were only lifted in 1965.

Authorities have banned protests in the Athens center. Outside the archbishopric offices where Francis was meeting Ieronymos, police escorted away an elderly Greek priest who was calling the pope a "heretic."

AFP