Brussels: European Union and Balkan leaders met Sunday to tackle the migrant crisis as Slovenia warned the bloc will "start falling apart" if it fails to take concrete action within weeks.
The mini summit, called by European Commission President Jean-Claude Juncker, grouped the heads of 10 EU nations, including German Chancellor Angela Merkel, plus the leaders of non-EU Albania, Serbia and Macedonia.
"This is an important opportunity to have them around one table," European Council President Donald Tusk told reporters in Brussels.
"Today we need a dialogue and talks among Balkan leaders to avoid unnecessary possible misunderstandings and tensions in the whole region."
More than 600,000 people have landed on European shores this year -- many of them fleeing violence in Syria, Iraq and Afghanistan -- in the continent's worst migration crisis since World War II.
Some 3,000 people have died making the dangerous Mediterranean sea crossing.
There have been scenes of chaos and suffering as migrants in their thousands make the gruelling journey up from Greek beaches through eastern Europe, heading for Germany and other wealthy northern EU countries.
Fears are rising that the crisis is threatening the "Schengen" system of borderless travel, one of the bedrock achievements of a united Europe.
Faced with a huge influx heading north, Hungary has closed off its borders with Serbia and Croatia.
Tiny Slovenia has now threatened to build border fences if it does not receive help, having become the main entry point to the Schengen zone following Hungary's clampdown.
"If we do not deliver some immediate and concrete actions on the ground in the next few days and weeks I believe the EU and Europe as a whole will start falling apart," Slovenian Prime Minister Miro Cerar warned as he arrived for the talks.
Slovenia, which numbers two million people, has been swamped by more than 60,000 migrants in a matter of days.
The numbers arriving in Slovenia are proportionate to half a million arriving in Germany in a day, Cerar said.
Cerar called on neighbour Croatia not to continue pushing migrants onward to Slovenia on their way to other countries in the EU.
Juncker had outlined 16 proposals for the talks, according to a draft seen by AFP on Saturday, including an undertaking that no country will let migrants through to an adjoining state without first getting the neighbour's agreement.