German Chancellor Angela Merkel and Greek Prime Minister Alexis Tsipras speak during the E.U. summit in Brussels on Oct. 15, 2015, held to discuss issues including the current migration crisis. (Martin Meissner/AP)

Stepping up European attempts to clear away hundreds of thousands of migrants whose asylum claims have been denied, E.U. leaders early Friday bolstered the powers of the pan-E.U. border agency to deport people.

The move highlights the flip side of a refugee crisis that has overwhelmed the continent and posed a challenge to some of the basic principles of the 28-nation European Union. European leaders have been bitterly divided about how to share the burden of the influx. They have been more unified about strengthening their borders to turn away migrants. The decision is likely to lead to an increased pace of deportations. It comes a month after E.U. leaders last met to force through a plan to spread 120,000 asylum seekers across the continent, over the objections of Central European countries.

Several senior E.U. leaders warned that the continent was not doing enough to accommodate the influx, and they said that an even larger wave of migrants could be provoked in the coming months by Russia’s military intervention in Syria in favor of President Bashar al-Assad. The bitter conflict in Syria has flared after government forces, backed by Russian air support since Sept. 30, renewed their assault on rebels after several months of losing territory.

“We are afraid that especially after the last action in Syria, the new wave can be bigger than now,” the European Council’s president, Donald Tusk, said ahead of the meeting. After the closed-door talks, the council president said that Europe’s border agency would receive hundreds more personnel and fresh powers to be more “proactive” in deporting migrants.

Nearly 600,000 people have crossed the Mediterranean this year to reach Europe, and Germany alone expects up to 1 million asylum seekers. Although people fleeing the conflicts in Syria and Iraq have generally been granted protection, Europe is turning away migrants from other countries who are found to have come for economic reasons.

A look at the numbers behind the stream of refugees flowing into Europe as political leaders struggle to ease the burden. (Jason Aldag/The Washington Post)

The sorting process has been a major challenge for countries that have struggled to handle the new arrivals. Germany is requisitioning vacant office buildings to shelter migrants. More than 178,000 asylum seekers have flowed through tiny Croatia in just the past month, challenging the facilities of a territory smaller than West Virginia. Hungary has built a border fence topped with razor wire. Other countries have reimposed border controls along long-dormant frontiers between E.U. territories.

The migrant situation creates “questions that are burning people in their souls,” German Chancellor Angela Merkel said, “because we have a very disorderly situation at the moment, and we need more order and more control.”

After the sorting — a legal track that can sometimes take years — the deportations are a deeply challenging process. Nations face the choice of buying tickets on commercial flights for people they want to send away or chartering flights, a costly option that is nevertheless a frequently used tool in Europe and the United States. Fewer than half of the migrants ordered deported from Europe are actually sent away, in part because of the practical challenges.

Friday’s decision gives Frontex, the European border agency, the power to organize chartered deportation flights on its own. Previously, its role was limited to funding and coordinating chartered flights only after an individual country decides to initiate such removal flights.

“There are a lot of people residing inside the European Union who are not entitled to be there,” said Yves Pascouau, director of migration and mobility policies at the Brussels-based European Policy Center. “The question is extremely difficult.”

Over the past year, many of the Frontex-coordinated flights have taken deportees back to the Balkan nations of Albania and Kosovo. Those countries are poor but generally free of the political persecution that is grounds for an asylum case. Other flights have taken migrants back to Nigeria, Pakistan and Colombia.

A look at the plan to resettle migrants across Europe

One July flight, for example, took migrants who had reached eight European countries back to Nigeria and Ivory Coast. At a cost of $366,000, 59 migrants were sent back on a flight organized by Austria. German authorities have vowed to step up deportations from their country and have said they are chartering flights nearly weekly to the Balkans. The German Parliament on Thursday approved measures to cut supports for asylum seekers and make deportations easier.

And in several high-profile cases in Britain, authorities have deported migrants to Afghanistan, a decision that has drawn criticism from human rights groups, which say that the country is too dangerous for people to be forcibly returned there. The most recent charter flight to Kabul was in late August.

At the meeting, E.U. leaders also began discussions about significantly stepping up aid to Turkey to help it deal with the more than 2 million Syrian refugees on its territory. Europe is considering up to $3.4 billion for Turkey, alongside liberalized visas for Turkish citizens to travel to Europe, in exchange for a Turkish agreement to improve conditions for refugees and to do more to keep them from traveling onward.

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