EU member Slovenia on Tuesday announced all migrants without a valid Schengen visa would be denied entry as of midnight, a decision that Serbia said "practically closes the Balkan route." Neighboring Croatia also announced that it would refuse the transit of most refugees, as countless migrants still seek to make their way to central Europe.

Concerned about "becoming a reception center for refugees," Serbia said it would align its policy by closing the border with Macedonia and Bulgaria to refugees and other migrants without valid EU visas.

Slovenia said it would still accept some migrants "on a case by case basis on humanitarian grounds" and allow those seeking asylum in the Alpine country, a statement from the interior ministry said.

Several hundred thousand refugees and economic migrants have plied the Western Balkan route over the past year on their way to northern Europe after making the Aegean crossing to Greece from Turkey.

Austria, Croatia and Macedonia have in recent weeks raised restrictions on entry in a bid to stem the flood of migrants moving further north to seek asylum in Europe.

The restrictions have left several thousand migrants stranded on the Greek side of the Macedonian border.

The domino effect comes as EU leaders at a summit on Monday said the irregular migrant flows along the Balkan route "have now come to an end."

The EU is trying to halt the disorganized influx of migrants - nearly half from war-torn Syria - that have divided the 28-member bloc and threatened to upend the cherished Schengen zone.

The move to close the Balkan route comes asthe EU and Turkey look set to strike a long anticipated migrant deal.

Under its terms, Turkey has agreed to accept Syrian and other migrants from Greek islands in exchange for EU countries taking some Syrians directly from Turkey.

The migrant deal also includes financial aid to Turkey, political concessions on visa liberalization for Turkish citizens and the acceleration of Ankara's EU bid.

cw/jil (AFP, AP, dpa, Reuters)