The Balkan route, which has been used for months by more than a million migrants from the Middle East and elsewhere to reach western Europe, is being closed after countries on the route announced stricter border controls on Tuesday.
Slovenia has reinforced its border crossing regime as of midnight and will allow through only migrants with valid passports and visas or those seeking asylum. Serbia has announced similar measures on its borders with Macedonia and Bulgaria.
As of midnight, Slovenia will fully apply the Schengen agreement on its border with Croatia in line with an agreement to close the Balkan migrant route, reached at the EU-Turkey summit in Brussels on Monday, STA news agency said.
Slovenian Prime Minister Miro Cerar said after the summit that the Balkan migrant route would be closed and that only migrants with valid documents would be allowed into the Schengen passport-free zone.
Croatian Interior Minister Vlaho Orepic told the RTL commercial television channel on Tuesday night that Croatia too would apply new rules and that only people with valid passports would be allowed across the border. "There has been a change to the regime. Europe has obviously embarked on a new phase in dealing with the migrant crisis. It has been decided that the Schengen countries will apply the Schengen rules," he said.
Orepic said that there had been no migrant arrivals in Croatia over the last two days, adding that before that between 400 and 500 had arrived daily.
"Europe's border will be on the Macedonian-Greek border and we will comply with the decisions made," Orepic said.
In the last 14 months 1.13 million migrants, fleeing conflict and poverty in the Middle East and north Africa, have arrived in Europe, mostly via Turkey and Greece, causing the worst migrant crisis since the Second World War. Turkey is currently providing shelter to 2.7 million Syrian refugees.
Last month Austria limited the number of asylum seekers it would take in, causing a domino effect of border closures on the Balkan route and leaving tens of thousands of migrants stranded on the border between Greece and Macedonia.