Refugees and migrants line up for a food distribution at a relocation camp in Schisto, near Athens. (Alkis Konstantinidis/Reuters)

Greece on Thursday recalled its ambassador to Austria for consultations, escalating a diplomatic war in Europe over how to handle a record influx of migrants from the war-torn Middle East and beyond.

The move underscored how European unity over the refugee crisis is quickly breaking down, leaving an every-nation-for-itself approach that threatens to escalate the scale of the humanitarian emergency confronting the continent.

In recent days, a group of nations led by Austria have upended attempts to forge a regional response by taking unilateral steps aimed at sharply limiting the number and type of migrants allowed to cross their borders.

Those moves, however, have left a growing bottleneck of thousands of would-be refugees trapped at their European entry point: near-bankrupt Greece. And on Thursday, Greek Foreign Minister Nikos Kotzias blasted what he suggested was a new nationalism spreading across the continent, a mentality reminiscent of the 19th-century divisions that led to decades of instability in Europe.

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“It is clear that the big problems of the European Union cannot be dealt with though mentalities and extra-institutional initiatives that have their roots in the 19th century,” Kotzias said in a statement. “Responsibility for the handling of the immigration and refugee crisis cannot fall on one country alone. Common sense requires that the principles of solidarity and equal distribution of the weight is the effective way to resolve this complex problem.”

Tensions between Greece and Austria have been escalating since last Friday, when Vienna announced a strict limit of 80 migrants a day allowed to apply for asylum on its territory. That sparked a chain reaction of nations eager to avoid logjams.

Key transit nations Macedonia and Serbia on Sunday moved to bar from entry virtually all Afghans, who make up about one-third of all migrants. They are allowing Syrians and Iraqis to cross. But even migrants from those war-torn nations are now being asked to produce more paperwork and identification, which many of them do not have.

The diplomatic crisis deepened Wednesday, after 10 nations held a meeting in Vienna to uphold their new policies limiting migrants. Greece lodged a formal protest after not receiving an invitation and then followed up Thursday by recalling its ambassador to Vienna.

The Austrians, who say nations along the migrant route must take action themselves because Europe has not come up with a working regional agreement, were unbowed. The recalled Greek ambassador, according to an Austrian foreign ministry official who spoke on the condition of anonymity, should now be able to inform his superiors about the real problems confronting nations such as Austria.

“We see a chance that the ambassador will inform the Greek authorities about the situation and challenges that destination countries on the refugee route, such as Austria, are facing,” the official said.

European nations have struggled for months to come up with a single regional solution, particularly with new arrivals this year already exceeding 100,000 migrants — a number far outpacing the same period in 2015. But any working deal seems more distant now than ever, even as diplomatic infighting intensifies.

The Greeks and the Germans are now bickering with the Austrians and the Balkan countries. The French are upset with the Belgians for new border controls aimed at blocking migrants trying to move from France into Belgium. Much of Europe, meanwhile, is pointing fingers at the anti-migrant government in Hungary for seeking to undermine a regional agreement struck last year to share the burden of migrants among all E.U. nations.

On Tuesday, Austrian Chancellor Werner Faymann dismissed criticism of his country’s decision by the European Union, saying, “We can do without this advice.”

Stephanie Kirchner in Berlin and Elinda Labropoulou in Athens contributed to this report.

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