The European Union has until a March 7 summit with Turkey to curb the flow of refugees into Europe or the bloc's fragile migration strategy could "completely break down," the European commissioner for migration warned Thursday.

At the summit, EU leaders — who have spent several months arguing over how to deal with the refugee crisis — will seek to push a strategy backed by Germany and the European Commission to stem the flow of refugees to Europe.

"In the next 10 days we need tangible and clear results on the ground otherwise there is the risk the whole system will completely break down," Dimitris Avramopoulos told reporters after a meeting of EU interior ministers in Brussels.

The ministers grappled to repair deepening divisions over their approach to the migration crisis, after a splinter-group move by Austria to seal borders triggered a chain reaction along the Western Balkan route, leaving thousands of refugees stranded in Greece.

Political tensions surrounding the issue escalated Thursday afternoon when Greece recalled its ambassador in Vienna and issued a sharply worded statement decrying actions "that have their roots in the 19th century."

"It is highly important that we stick together in Europe," Thomas de Maizière.

Although Avramopoulos, who is Greek, tried to play down the diplomatic row, saying "the ambassador was called back for consultation, they didn't break the relationship," there were heated exchanges between the Greeks and Austrians in the meeting.

"The Austrian minister had quite a intense clash with her Greek counterpart," said a source who was inside the room.

Vienna confirmed the row but held its ground. Interior Minister Johanna Mikl-Leitner told reporters she spoke to her Greek counterpart, Ioannis Mouzalas, and told him Austria had no reason to believe that the EU's external border in Greece is properly protected.

“If Greece … is not able to secure the EU's external borders, we have to ask if the Schengen border can still be there,” she said.

Mouzalas also came in for criticism from Eastern European countries for what they called a failure by Athens to deal with the refugee flow. But Germany defended Athens, diplomats said.

Mouzalas told journalists before the meeting that Greece did not want "to become the Lebanon of Europe" — the Mediterranean country of 4.5 million inhabitants that is hosting about 1.5 million Syrian refugees.

“There were controversial debates over the action of some European states and neighbor countries, particularly the Western Balkan states, which thought it is right to implement individual measures,” Germany's Thomas de Maizière told reporters at the end of the summit.

Austrian breakaway

The day before, Austria and several other countries, including non-EU members, agreed on their own steps to halt the migrant flow, imposing tougher restrictions on which refugees would be allowed to enter and stricter rules on who could stay. The meeting, which produced a Vienna Declaration calling for the migrant flow along the Western Balkans route to be "substantially reduced," was held despite calls from European leaders over the past week to keep in line with a broader strategy.

The ministers' summit in Brussels was aimed at trying restore a coordinated effort. Before it started, de Maizière called such independent national actions "a bad choice," and implored his EU counterparts to work together on a common effort to protect external borders.

“Right now the unity of the Union and human lives are at stake,” Dimitris Avramopoulos.

"It is highly important that we stick together in Europe," de Maizière told reporters before the ministerial meeting. "If national initiatives gain the upper hand, all will suffer damage. We see alternative routes that will be used instead. And that’s why Germany will do everything to make the protection of the external border between Turkey and Greece a success, and if not, that we undertake common measures.”

New tensions also emerged on other borders. French Interior Minister Bernard Cazeneuve said before the meeting that Paris had not been informed of Belgium’s decision to reinstate border controls at its frontier with France.

Belgium justified the decision because Paris is moving forward on a plan to evacuate the Calais "Jungle" refugee camp that houses around 4,000 migrants and Brussels is afraid this could create massive migration towards Belgium. Cazeneuve denied the intention to send bulldozers to the camp and reassured that it will be evacuated in an orderly manner without creating a flow towards Belgium.

With so much at stake, Avramopoulos called Thursday's meeting “a critical moment” in the effort to stem the flow of refugees from the Middle East through the Balkans and toward northern Europe.

"Lonely initiatives do not lead anywhere," he said. “Right now the unity of the Union and human lives are at stake.”

However, next month's EU-Turkey summit might not produce the results Avramopoulos seeks. It remains unclear if Turkey will deliver on the action plan it agreed with the Commission last October. The agreement demands Turkey stops refugees from taking off from its shores to reach Greece.

“There are indications that not only the weather influences the numbers [of refugees crossing the Aegean Sea] but also the actions of the traffickers and (efforts on) the Turkish side," de Maizière said at the end of the meeting.

The president of the European Council, Donald Tusk, is planning a visit to Ankara along with the Commission's first vice president, Frans Timmermans, before the March 7 summit, said a diplomat, but the date has not yet been agreed.

"That is a very crucial date to see to what extent we succeed in lowering the influx towards Europe as a whole or we have to take other measures to deal with the influx," said Klaas Dijkhoff, interior minister of the Netherlands, which currently holds the EU's rotating Council presidency.

'Warehouse of souls'

Greece had already raised serious concerns about the Vienna decision. Prime Minister Alexis Tsipras said Wednesday in parliament that he will not allow his country to become a “warehouse of souls” and threatened to block future EU agreements on the refugee crisis if member states do not share the burden.

Vienna last week announced it would cap the number of asylum claims it would process every day and that it would allow no more than 3,200 migrants to transit the country per day. The Commission branded the decision illegal in a scolding letter to Vienna, but Austria went ahead with its plans. After the issue bogged down summit discussion last week, the country continued to push the issue by convening the meeting in Vienna Wednesday.

However, Avramopolous ruled out the Commission forcing Vienna to respect EU rules using so-called infringement procedures. "Nobody has ever talked about it," he said.

Ministers also voiced concerns about Hungary's decision Wednesday to call a referendum on the EU’s mandatory quota system for relocating refugees.

Austria has refused to budge. “I made clear that Austria will not move away from the decision of its government, that we will keep our limit of 37,500,” Mikl-Leitner told reporters.

Other countries also took matters into their own hands. Earlier this week, Slovenia said it would beef up controls on its border with Croatia as Serbia and Macedonia were both looking at curbing the flow of refugees from Greece.

To ease tensions ahead of the summit, some EU ministers held a working breakfast Thursday with their colleagues from several countries, including Serbia and Macedonia. During the week ambassadors from the Balkan countries met with the EU's Dutch presidency to try to coordinate action, said a diplomat.

“It's a situation that can develop very rapidly, the important thing is that other countries are not caught by surprise,” the diplomat said.

Ministers also voiced concerns about Hungary's decision Wednesday to call a referendum on the EU’s mandatory quota system for relocating refugees. Prime Minister Viktor Orbán accused the EU of an “abuse of power.”

“If we generalize the use of referenda, we are in a way creating the basis for unmaking the European Union,” Spain's minister of home affairs, Jorge Fernández Díaz, told reporters.

Barbara Surk and Hans von der Burchard contributed to this article.