Leaders of nations along the Western Balkans migration route agreed Sunday to impose tighter controls on the flow of refugees from the Middle East to Europe, committing to provide shelter for an additional 100,000 asylum-seekers and to refrain from waving migrants through to other countries.

The agreement for closer coordination among 11 countries, including three from outside the EU, came after a lengthy struggle to reach a compromise on a key operational point: How many asylum-seekers should be sheltered in Greece, the country where most of them first arrive.

After what sources in the room called “tense” discussions, Greece agreed to provide shelter for an additional 30,000 refugees before the end of the year, plus another 20,000 with help from international organizations. An additional 50,000 refugees will be sheltered elsewhere along the Western Balkans route.

“The only way to restore order is to slow down the migration flows,” said European Commission President Jean-Claude Juncker after the meeting. “We have made to clear to everyone this evening that waving [refugees] through has to be stopped.”

German Chancellor Angela Merkel cautioned that the agreement “doesn’t solve the overall problem. It’s just a contribution to what is a more reasonable way of dealing with the problem… Further steps will follow this which will lead to a solution.”

The short-term fixes agreed to Sunday night also included the creation of permanent “contact points” to allow regular information exchanges among countries, and immediate incentives to provide additional humanitarian aid to refugees in the region.

The countries will also work to increase border-control efforts, with the EU agreeing to send 400 police officers “within a week” to Slovenia. There was also a commitment on the part of the countries to do a better job of registering arrivals of migrants and returning those deemed ineligible for asylum in Europe.

Sources said leaders insisted on pushing Greece to do a better job of guarding its borders and processing the inflow of migrants. Imposing on Athens a requirement to shelter more refugees was seen as way to demonstrate that “Greece needs to take up its responsibilities.”

According to one source in the room, the atmosphere in the meeting was “tense,” with Merkel, who is under increasing political pressure at home to deal with a record influx of refugees, telling other leaders that the EU is in “a very fragile situation.”

Another source, surprised at the level of alarm from Merkel, interpreted the remark as a warning that failure on this issue would lead to the “end of the EU as we know it.”

Asked about her remarks after the meeting, Merkel said “this is one of the biggest tests Europe has faced ever. We are confronted with global conflicts that touch us now directly, and in such a situation Europe must demonstrate that it is a continent of values and solidarity.”

But that solidarity was not always on display during the meeting. At one point the tension flared in a clash between Croatian Prime Minister Zoran Milanović and his Slovenian counterpart Miro Cerar, whose common border has become the newest flashpoint in the refugee crisis. According to a Slovenian diplomat, Milanović was too “aggressive” in the meeting.

Short-term solutions

Juncker, who called the mini-summit at Merkel’s request, had urged the leaders to focus on “practical, operational” solutions to address short-term needs in the crisis, rather than big-picture political disputes, according to an EU official with knowledge of the talks.

“[Juncker] told leaders, ‘Please tell us what you need,’” the official said. “They are not looking to redefine a new European policy on refugees. This is about concrete, specific operational improvements.”

The unusual nature of the meeting was highlighted by the press conference afterward, which featured Juncker and Merkel, who convened this summit, and UN High Commissioner for Refugees António Guterres but not Donald Tusk. The European Council president normally presides over full EU summits but was merely an attendee at this gathering.

Speaking to reporters after the first summit session had concluded and before a dinner with the leaders had begun, Serbian Prime Minister Aleksandar Vučić said the meeting had been useful if only because it opened lines of communication among the countries along the migration route.

“At least we had a chance to speak to each other, to hear each other and to learn a bit about the problems that all the others are facing,” Vučić said. “I’m not sure that we’re going to conclude something that would be very helpful immediately but I’m sure that at least we understood each other and we’ll be ready to take actions jointly in the future.”

Not every leader was interested in speaking during the meeting, according to a source in the room: When asked to speak by Juncker, Hungarian leader Viktor Orbán declined.

“What matters now is delivery,” said Tina Strefela, spokesperson for Slovenian leader Cerar. “We need leaders to stick to the political commitments agreed upon, and that has to start tomorrow.”

Details of the agreement were left to be worked out in the coming days and weeks at ministerial level. But even before the meeting began on Sunday there was dissatisfaction among participants over a draft statement calling on countries along the Western Balkans migration route to stop letting refugees pass through their borders.

Croatia’s Milanović lashed out at the proposal Saturday, saying “whoever wrote it does not understand how things work, he woke up from several months dreaming. There will be no obligations for Croatia … not a single one.”

As he arrived at the meeting Sunday, Milanović reiterated that he would not support the imposition of “any further commitment or obligations” on the countries. “I came to discuss, not to adopt a joint conclusion, which leads nowhere,” he said.

The meeting was held amid mounting difficulties facing Europe, which is struggling to cope with a migration crisis that keeps on shifting. Even as leaders discussed how to deal with the crisis the composition of the flow is changing rapidly, according to data from Macedonia, one of the transit countries in the route.

The number of Syrians, who are eligible for refugee status, is decreasing while the number of other migrants is on the rise. Syrians transiting Macedonia have decreased from nearly 90 percent of the flow in August to about 60 percent in October while the number of Afghans, who do not qualify for the status of refugee, has been rising and now they represent almost 20 percent of the flow.

“The refugee corridor is turning into a migrant corridor,” Macedonian President Gjorge Ivanov told POLITICO. The country, with only 2 million inhabitants, has seen so far this year 420,000 refugees and migrants transiting its territory, government data show.

Slovenia last week called for increased protection of the EU’s external borders after turning into the latest frontline in the crisis. Last Tuesday Slovenia mobilized its army to deal with the sheer numbers of migrants arriving at its borders after Hungary closed its border with Croatia.

With a population of around 2 million, Slovenia claims to be overstrained by the influx and asked the Commission last week for €60 million over the next six months to aid the handling of refugees.

‘The situation is serious’

“The situation is truly serious,” Cerar told reporters as he arrived at the meeting. “If we don’t deliver some immediate and concrete actions on the ground in the next days and weeks, I believe the whole European Union and Europe as a whole will start to fall apart.”

In Greece, the number of arrivals by sea this year has now passed the half-million mark with the arrival last Monday on the Aegean islands of nearly 8,000 people, the UNHCR said. “Many of the refugees and migrants are desperate to quickly move onwards, fearing that borders ahead of them will close,” the UN refugee agency also said.

The document also includes measures still to be finalized, such as setting up a new operation by the EU’s border control agency Frontex at the external land border between Greece and Macedonia and Albania.