Poland ready to impose border controls: PM

Poland will impose border controls at the first sign of "any threat" amid Europe's worst migrant crisis since World War II, its prime minister said Monday on the heels of border clampdowns by EU neighbours.

"As soon as I hear there is any kind of threat to Polish borders, controls will be imposed," Prime Minister Ewa Kopacz told reporter in Warsaw as southern EU neighbours the Czech Republic and Slovakia tightened their borders.

Unlike EU neighbours Austria and Hungary, the Czech Republic, Poland and Slovakia have seen few refugees and migrants seeking to transit through their territories to Germany in recent months.

All are part of the Schengen passport-free travel zone, to which most EU members belong.

Kopacz also reiterated Poland's rejection of fixed refugee quotas and demanded very tight controls on the EU's external borders hours ahead of a key meeting in Brussels focused the European Commission's plan which involves a quota system for distributing 160,000 refugees around the bloc.

"Poland won't agree to automatic refugee quotas. Poland demands very, very strong controls on the EU's external borders," Kopacz said.