Ministers from EU and Balkan nations are meeting in Brussels to try to heal divisions over a migrant crisis that could threaten the bloc's survival.
Austria, Serbia and Macedonia have taken steps to restrict entry to migrants, angering Greece, which fears the controls will cause a bottleneck.The rift places further strain on a common EU migration policy, already in disarray over the surge in migration.
More than 100,000 migrants have reached Europe this year, most via the Balkans.
European Council president Donald Tusk has warned that the failure to make progress towards resolving the crisis could increase the likelihood of the UK voting to leave the EU this year.
The EU interior ministers meeting in Brussels will hear plans drawn up by Austria and eight Balkan countries that seek to restrict the numbers entering their borders.
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The countries have also pledged to accept only those they deem to be in need of protection, which has already been interpreted by some governments as meaning only Syrians and Iraqis.
Macedonia enacted the measures at its border with Greece over the weekend, barring entry to Afghans, who make up many of the migrants.
Austrian Interior Minister Johanna Mikl-Leitner described the measures as a "chain reaction of reason" and warned that the crisis could threaten the EU's survival if it was not brought under control.
But the plans drew sharp criticism from Greece, which threatened to block all decisions at an upcoming EU migration summit if member states did not agree to take in quotas of migrants.
Greek Prime Minister Alexis Tsipras said his country was turning into a "permanent warehouse of souls" and should not be left to deal with the crisis alone.
"From now on, Greece will not agree to deals if we do not secure the mandatory sharing of the burden and responsibility proportionally among member states," Mr Tsipras said.
