Can Chancellor Merkel help EU states find common ground and persuade them to act in concert? And what will Turkey do? DW's Brussels correspondent Barbara Wesel summarizes the challenges ahead at Monday's big summit.
There's no need for Chancellor Angela Merkel to change course. Other EU member states have done it already, moving around her. Now that the Balkan route has been closed, fewer refugees are arriving in Germany, taking the pressure off the chancellor.
However, Merkel still sees the EU's political dangers and continues to seek a joint solution. Europe's capacity for action and the retention of the Schengen zone are important to her. This is also why she's backing the European Commission's initiative to seal the EU's external borders by the end of the year, to enable all the temporary controls by individual member states to be rescinded.
In this regard, the chancellor's attitude toward Greece will be both strict and lenient. On the one hand, Merkel has criticized the chaos there, and the Greeks' tardiness in building refugee accommodation.
On the other hand, she has called for solidarity with Athens and promised EU support. The EU Commission has already promised 700 million euros ($769 million) in emergency aid, and Merkel fears the potential destabilization of economically beleaguered Greece.
However, unlike with Hungary last year, she is refusing to take in the refugees currently stranded on the Greek-Macedonian border. Berlin's dispassionate comment is that the challenge Greece is facing is not "unreasonable." In addition, the German government said the aim was to put a stop to refugees simply being waved through toward the north.
Tsipras: the victim
The main demand of Greek Prime Minister Alexis Tsipras will be for the burden of caring for the refugees to be fairly distributed among the EU states. He has complained that his country is facing a humanitarian crisis as a result of other states closing off the Balkan route.
"The task is too great for us," Tsipras said before the summit. However, other countries have only limited sympathy: for months, Tsipras stubbornly evaded all the EU's demands that Greece set up reception centers and hot spots for the screening of refugees.
Now Tsipras must act at lightning speed. Many are accusing him of being partly responsible for the escalation in the refugee crisis, saying he did nothing whatsoever to secure the maritime border with Turkey. Around 2,000 people a day are still arriving on the Greek islands by boat.
Faymann: the conspirator
Austrian Chancellor Werner Faymann usually sends his interior minister to defend his country's refugee quotas and border closures. However, at this summit the Austrian leader will have to look Merkel, and her criticisms, in the face.
Merkel has accused him and the Balkan countries of tipping the EU into crisis by closing their borders, and holds him jointly responsible for the chaos in Greece.
And this despite the fact that Faymann was still regarded last year as one of Merkel's close allies. Increasing support for right-wing populists and the threat of fresh elections have prompted his about-face. This aside, Faymann is suggesting sharing the financial burden: like the bank bailout fund, he wants there to be a refugee fund that everyone pays into.
Turkey: the unpredictable
Speaking to the press on Friday, EU Migration Commissioner Dimitris Avramopoulos said cooperation with Turkey was key. That sentence could be the motto for the meeting. The question is whether the Turkish Prime Minister Ahmet Davutoglu is willing to fulfill Europe's wishes, which include keeping the vast majority of refugees within Turkey's borders and taking action against people smugglers.
The EU sees it as a good sign that Turkey has now, for the first time, taken a few hundred migrants back from Greece. In exchange, the Europeans will pay 3 billion euros to provide for them. Turkish President Recep Tayyip Erdogan has, however, already scoffed at this figure, saying it's far too low.
EU accession negotiations are also to move forward, and the Turkish president will be invited to EU summits. Finally, Turkey's most important demand is the introduction of visa-free travel to Europe, as early as this October.
The deal will be a test for the European Union. Politically speaking, it's already hard to swallow the revival of Turkey's war against the Kurds, and its ambivalent role in the war in Syria. Now, though, the European Parliament President Martin Schulz has said the storming and closure of an anti-government newspaper show that "Turkey is in the process of gambling away the historic opportunity for rapprochement with Europe." Schulz said there could be "no discount" for Turkey when it came to observing core values.
However, representatives from Ankara are happy to point out that their country has the upper hand. In an interview with the BBC on Friday, Turkey's EU ambassador Selim Yenel explained that the flow of migrants could be set in motion again at any time, if the EU did not meet all of Turkey's demands. With these signals coming from Turkey, the hope of achieving cooperation on refugee policy looks questionable, before the summit even begins.