The spiritual leader of the world’s 200 million Eastern Orthodox Christians brings an agenda spanning religious, political and environmental issues to a 12-day U.S. visit beginning Saturday that includes a meeting with President Joe Biden and various ceremonial and interfaith gatherings.

Making the latest of several trips to the country during his 30 years in office, Ecumenical Patriarch Bartholomew is expected to address concerns ranging from a pending restructuring of the American church to his church’s status in his homeland, Turkey.

Bartholomew’s title, patriarch of Constantinople, reflects the ancient imperial name of the city now known as Istanbul in a country where Orthodox Christians, who are mostly ethnically Greek, are a small minority.

Archbishop Elpidophoros of the Greek Orthodox Archdiocese of America said the patriarch is expected to renew calls for the reopening of a school of theology closed by the Turkish government 50 years ago.

“Religious freedom in Turkey is vital for the ecumenical patriarchate in Turkey,” Elpidophoros said.

Bartholomew will receive an honorary degree from the University of Notre Dame on Oct. 28 in an event highlighting efforts to improve Orthodox-Catholic ties, centuries after the two churches broke decisively in 1054 amid disputes over theology and papal claims of supremacy.

Repairing that breach has “been a longstanding commitment of the patriarch,” said the Rev. Alexis Torrance, a professor of Byzantine theology at Notre Dame and an Orthodox priest.

The gathering will also include a talk on environmental stewardship, underscoring Bartholomew’s reputation as the “green patriarch.”

The patriarch is considered first among equals in the Eastern Orthodox hierarchy, which gives him prominence but not the power of a Catholic pope.

Just as his influence is limited in Turkey, it is also limited in the Eastern Orthodox communion, rooted in Eastern Europe and the Middle East with a worldwide diaspora. Large portions of the communion are in national churches that are independently governed, with the ecumenical patriarch having only symbolic prominence, though he does directly oversee Greek Orthodox and some other jurisdictions.

The Russian Orthodox Church, with about 100 million adherents, has in particular asserted its independence and influence and rejected Bartholomew’s 2019 recognition of the independence of Orthodox churches in Ukraine, where Moscow’s patriarch still claims sovereignty.

For an ecumenical patriarch with primarily soft-power tools such as diplomacy at his disposal, the high profile of the U.S. visit has symbolic value for Bartholomew, said Andrew Walsh, associate director of the Greenberg Center for the Study of Religion in Public Life at Trinity College in Connecticut.

It will “demonstrate that he’s a respected leader,” said Walsh, a layman who has long written about contemporary issues in Orthodoxy. “It is useful and desirable for him to show that presidents of the United States will talk with him.”

Bartholomew is set to meet with Biden and other top U.S. officials in the coming days, though exact times have not been announced.

Bartholomew will also hold a ceremonial door-opening at St. Nicholas Greek Orthodox Church and National Shrine in New York City, built to replace a parish church destroyed during the 9/11 attacks, and to memorialize those killed at the nearby World Trade Center.

Bartholomew will meet, too, with leaders of the Greek Orthodox Archdiocese of America and various other Orthodox leaders.

Last year his office suspended the Greek Orthodox archdiocese’s governing charter, and discussions are expected to yield a new one by 2022, according to Elpidophoros.

“What Greek (Orthodox) are waiting for is what he says about the charter” during the visit, Walsh said, particularly on the patriarch’s vision for how much authority will be centralized or decentralized in the American church.

The American Jewish Committee is recognizing Bartholomew with its Human Dignity Award for his environmental and interfaith work.

“He is not only the ‘green patriarch,’ but also he’s the patriarch of promoting dialogue,” Elpidophoros said.

A 2017 Pew Research Center report found that there were about 200 million Eastern Orthodox worldwide. It reported about 1.8 million Orthodox in the United States, with nearly half of those Greek Orthodox.