By Jan Lopatka and Robert Muller
PRAGUE (Reuters) - The European Union must provide support to western Balkan countries outside the bloc to help them halt the flow of migrants north from Greece towards the heart of the EU, Czech Prime Minister Bohuslav Sobotka said on Thursday.
In an interview with Reuters, Sobotka hailed steps by western Balkan nations to stop an uncontrolled influx into the EU via their territory of people fleeing from war or failed states across the Middle East and Africa.
"Today the situation is that countries in the western Balkans are willing to regulate migration and Europe must unequivocally support them in that," he said in an interview.
The European Union will hold an extraordinary summit with Turkey on March 7, followed by a regular European Council meeting on March 18-19, both focusing on migration.
Sobotka said he understood the decision by Austria last month -- condemned by Greece and Germany -- to cap the number of migrants entering that country, which has caused a domino effect of border closures through the Balkans and left up to 30,000 people stuck in Greece as Macedonia refused to let them in.
Sobotka said Austria had in effect launched the "Plan B" of restricting the flow of migrants out of Greece, an idea pushed by the Visegrad Four group of central European countries comprising the Czech Republic, Poland, Hungary and Slovakia.
Austria's move has been denounced by German Chancellor Angela Merkel, who has said financially strapped Greece could not be left to cope with swelling migrant numbers alone.
Merkel said the best way forward was to implement an EU deal reached with Turkey late last year to stem the stream of people from there across the Aegean Sea to Greece.
Sobotka called for a number of complementary measures, including the provision of more aid to Greece given that migrants can no longer freely exit to the north.
"Germany does not want Greece to be neglected, and I do not want that in any way. We understand the consequences to Greece of closing the Balkan route, and Greece needs to get maximum help."
Asked about German opposition to closing borders, he said: "Austria and Germany are at full capacity (for accepting migrants) and I believe Germany sooner or later will support measures in the western Balkans."
The Visegrad Four - all former Communist states wary of non-European immigration - have opposed a majority EU foreign ministers' decision to relocate 160,000 refugees from Greece and Italy across the 28 member countries.
Sobotka said the Visegrad group would also oppose any more compulsory resettlement proposals such as one to transfer refugees directly from Turkey to EU countries in an orderly way. Resettlement from Turkey could however be done on a voluntary basis by some EU countries, he added.
The EU is pressing Ankara to cut the number of migrants reaching Greece by sea to less than 1,000 a day, in return for taking refugees directly from Turkey.
(Editing by Mark Heinrich)