Western Balkan countries would be worst hit by the collapse of Schengen, Slovakia's Foreign Minister Miroslav Lajcak has warned.

Lajcak also believes the conditions have not been met for Bosnia-Herzegovina to become a candidate country for EU membership in February.

He has also called on the authorities in the Republika Srpska (RS) "to stop threatening with a referendum."

The migrant crisis has put the Schengen agreement at serious risk. If it fails, the Western Balkan countries will suffer the biggest blow, Lajcak said in an interview to the Banja Luka-based Nezavisne Novosti.

However, we do not have a proper strategy at the European level, countries make decisions on their own, and this only shows how important it is that the EU reaches a realistic and feasible strategy for resolving the issue of migrants, Lajcak said.