They agreed to conduct regular dialogue at the operational level between the US, EU and Southeast Europe to "counter global security threats".

The leaders called for "effective and efficient global solutions to combat, prevent and address the root causes of radicalism, violent extremism and terrorism, which affect us all".

Broader international cooperation, as well as better coordination and sharing of information by law enforcement agencies is vital, the statement says.

"The present dramatic migrants 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 migration pressure on afflicted countries," reads the statement.

The statement was adopted at a meeting of the presidents of Slovenia, Croatia, Serbia, Montenegro, Albania, Kosovo and Bosnia-Herzegovina.

They were joined by US Vice-President Joe Biden and EU President Donald Tusk. Austrian President Heinz Fischer attended as a guest.

Slovenian President Borut Pahor, who co-hosted the summit together with his Croatian counterpart Kolinda Grabar-Kitarović, said that the region was committed to working for peace, security and prosperity.

Praising the goals of the Brdo-Brijuni Process, Pahor said: "We live in a world needy of positive and uplifting stories...and Brdo-Brijuni is such a story."

Echoing the sentiment, Grabar Kitarović said "a consolidated Europe is possible only if all countries in SE Europe join the EU".

She said that Slovenia and Croatia would continue to support all countries in the region in their efforts to join Euro-Atlantic organisations and implemented the necessary reforms.

The meeting comes at a time of heightened tensions in the region precipitated by the huge flow of refugees along the Balkan migration route.

The statement refers to these tensions in stating that "outstanding bilateral and regional issues should be constructively addressed, according to international law and its principles."

The leaders agreed that to achieve the common aims of strengthening the stability, security and prosperity of the region, it was necessary to "continue to strengthen the transatlantic partnership...and to re-energize the EU enlargement process for candidate countries and the Euro-Atlantic integration process for NATO aspirants."

Some countries are experiencing challenges in their individual progress on the European integration path, "contributing to a sense of discouragement and providing fertile ground for populism and instability that often thrive on unresolved political and inter-ethnic tensions".

"Active support for EU enlargement among EU Member States may be adversely affected, reinforcing this negative pattern, which must be broken on both sides," reads the statement.

The US vice-president maintained that, despite the open issues, the region had made important strides in recent years. Like the hosts of the meeting, Biden said without the integration of the countries from SE Europe it would be impossible to achieve a Europe "whole, free and at peace".