ROME— Hoping to cash in some of the political muscle he’s earned with his global popularity, Pope Francis will visit the Greek island of Lesbos on Saturday to try to spark a global political and humanitarian response equal to the current global immigration crisis.

For the outing, defined by a Vatican spokesman as “humanitarian, not political,” the pontiff is partnering with two Orthodox patriarchs, in an ecumenical coalition despite the millennial-old division between Eastern and Western Christianity.

Francis will visit the island with Ecumenical Patriarch Bartholomew of Constantinople and Orthodox Archbishop Ieronymos II of Athens and all Greece.

“I will go together with my brothers to express our closeness and solidarity to the refugees, the citizens of Lesbos and to all the Greek people who have been so generous in welcoming them,” the pope said April 13 at his weekly general audience.

The five-hour foray will include a visit to the Moria refugee camp-turned-detention center, where the three leaders will have lunch with the refugees, and a prayer service for migrants who’ve died trying to reach Europe. It comes as the continent struggles with a vacuum of leadership in dealing with the thousands of refugees arriving each month.

Numbers on the European refugee crisis

According to the International Organization for Migration (IOM), more than 150,000 migrants and refugees arrived in Greece between Jan. 1 and April 7, 2016, and more than half landed on Lesbos.

Some 366 people never made it, dying in their attempt to cross the Aegean Sea from Turkey to the island.

The IOM also estimated that over one million refugees arrived in Europe last year, most coming from war-torn Syria, Afghanistan and Iraq, where they’re fleeing religious persecution and violence, but also from Albania, Kosovo, Pakistan, Eritrea, Nigeria, and Iran.

In smaller yet significant numbers, there are also thousands of refugees fleeing conflict in Ukraine, where the country’s army is fighting Russian-backed separatists.

Many of those who make it to Europe claim asylum, with Germany receiving the highest number of new asylum applications in 2015, more than 476,000.

The IOM says that more than 1,011,700 immigrants arrived in Europe by sea in 2015, and almost 34,900 by land.

From the Middle East, most take a short voyage from Turkey to Greek islands such as Lesbos, but also Kos, Chios and Samos, often in flimsy rubber dinghies or small wooden boats.

Some 800 people died crossing the Aegean Sea last year.

Many of those arriving from Africa try to reach Italy across the Mediterranean Sea, arriving at the island of Lampedusa, which was Francis’ first destination outside Rome in July 2013.

In lesser numbers, others have Spain as their first destination within Europe.

Before getting on their boats, most migrants and refugees spend days on foot trekking across deserts, mountains, and war-torn countries.

Deal between Europe and Turkey

Pope Francis’ visit to Lesbos comes only weeks after the European Union reached an agreement with Turkey, in what officials claim is a solution to the problem on the Greek islands.

In a nutshell, the idea is that virtually all illegal immigrants will be sent from the Greek islands back to Turkey, from where they’ll be able to request asylum. As per the accord, for each refugee sent back, one will be granted asylum.

Yet putting the plan into practice is a challenge of Herculean proportions: Every reception center in the “hot-spot” areas will become a “detention center,” tribunals have to be set up to ensure that every refugee has their case heard, and Turkish police officers will have to go to the islands to help Greek police after the two countries have spent decades essentially ignoring each other.

In the words of German chancellor Angela Merkel, “I have no illusions that what we agreed today will not be accompanied by further setbacks.”

The UN refugee agency (UNHCR) had no direct input on the set-up, it’s not fully participating in the agreement, and has raised concerns.

So has Amnesty International, with the agency accusing the EU of “turning its back on a global refugee crisis, and willfully ignoring its international obligations.”

Joshua Kyller, an American coordinating the work of Catholic Relief Services in Greece and other countries, said that he, like the leaders who signed off on the deal, understand that it’s not going to resolve the problem.

“It wasn’t done in bad faith,” he said. “But it was done to buy time to, hopefully, develop a more systematic, humane way to solve this crisis.”

Catholic Relief Services is the overseas development arm of the U.S. Catholic bishops.

Kevin Appleby, International Migration Policy Director for the New York-based Center of Migration Studies, raised other concerns, such as the fact that migrants have already been sent back to Turkey, where they aren’t safe, and this has been done without the appropriate due process.

Appleby denounced the deal as a “deterrent strategy,” saying Europe is trying to send a signal to Syrian refugees that the continent is no longer open, which puts them in further danger.

Short-term v. long-term

Kyller told Crux that as an aid worker he’s concerned for the well-being of the refugees, both in the short and long term.

“This is an ongoing crisis,” he said, adding that the deal “in no way marks the end of our work.”

CRS in Europe is working together with the local branch of Caritas, and according to Kyller they’re mostly able to meet the migrants’ immediate needs, such as shelter, water, clothing, and food. They also have legal assistance in some of the detention centers, as well as internet access and basic medical assistance.

However, he asked, “what about school, education, jobs?”

Appleby highlighted that Europe today can be considered the “immediate crisis,” but immigration is a global crisis, “and this is not going to end anytime soon.”

“Around the world, in Africa, Latin and Central America, in Asia, people are fleeing persecution, hunger, war, and the response has been to deter or block them,” he said.

The fear factor

Fouad Twal, Latin Patriarch of Jerusalem, called for Europeans “not to be afraid” of migrants.

Speaking in Rome on Thursday at the Pontifical University of the Holy Cross, he said that before closing the doors to the refugees, Christians should remember Jesus’ words: “I was hungry and you gave me food, I was a stranger and you welcomed me.”

“Iraqi and Syrian Christians have lost it all, but their faith, they could have saved themselves if they converted to Islam, but instead, they lost it all,” he said. “In Europe, there’s no courage to lose anything.”

If you don’t want the refugees, he said, then “help these countries find peace. But for economic interests, for selling guns, we make war … They’ll happily stay in their homes, if we helped their countries be at peace.”

Appleby played down the risk immigrants pose.

“There’s always the possibility that someone gets in who has intent to harm, but the evidence shows that a lot of these terrorists are home-grown and converted after they arrive, or they come through an easier route, with a visa,” he said.

Papal politics

The son of immigrants himself, Francis has been an outspoken supporter of immigrant rights from the beginning of his pontificate.

In 2013 he went to Lampedusa, where he spoke of a “globalization of indifference” towards migrants.

Last September, he opened the Vatican to welcome two refugee families and urged every European church, convent and monastery to do the same.

In January, while addressing the diplomatic corps accredited to the Vatican, he signaled that immigration as going to be his top social concern for 2016, just like climate change was in 2015 and human trafficking had been in 2014.

This February he made a point of going to the U.S. border during his trip to Mexico. On the way back, he got in a spat of sorts with Republican presidential candidate Donald Trump, telling reporters that anyone who wants to build a wall to keep migrants out “is not Christian.”

The pope, through his spokesman, has tried to avoid turning this trip into a political photo-op, but the short visit is bound to have political impact, beyond the hope his presence can bring to the 3,000 refugees stuck in the Moria camp.

His visit comes only weeks before the United Nations’ World Humanitarian Summit, scheduled for May 23-24 in Istanbul, and Francis is on record saying that he hopes the encounter succeeds in “placing the person and human dignity at the heart of every humanitarian response.”