Dusan Stojanovic

ZAGREB, Croatia: Former Balkan rivals on Wednesday pledged joint efforts with the United States and the European Union in protecting European borders from a record surge of asylum-seekers amid fears that Islamic militants may have infiltrated the flow.

Southeast European leaders met at an urgent summit in the Croatian capital attended by U.S. Vice President Joe Biden to discuss the crisis that has seen hundreds of thousands of people fleeing war and poverty in the Middle East, Asia and Africa cross the Balkans.

“The present dramatic migrant crisis poses an unprecedented challenge from both humanitarian and security aspects, requiring dialogue and agreement to better protect the EU’s external borders and substantially alleviate migrant pressure on affected countries,” a declaration issued after the summit said.

Without outlining concrete border measures, the declaration added that for lasting peace and stability of the once war-ravaged region, all countries should have the option of joining the European Union and NATO.

The summit included all former Yugoslav states and Albania, of which only Slovenia and Croatia are both in the European Union and in NATO.

Biden’s trip came amid a heated debate in the U.S. about whether to admit Syrian refugees following the Islamic State group’s Nov. 13 attacks in Paris that left 130 dead.

At least two of the militants involved in the Paris attacks had passed through Greece, apparently posing as asylum-seekers.

“The refugee crisis is restraining the resources of the countries in the region,” Biden said. “It is clear there is a need to improve cross-border cooperation, information sharing to deal with the flow of refugees, while stepping up the capability to counter the terrorist threats as well.”