U.S. Vice President Joe Biden is attending the annual summit of Southeast and central European leaders in the Croatian capital, Zagreb, with the surge of refugees and migrants into Europe high on the agenda.
Wednesday's summit is also focusing on the fight against terrorism and the European Union accession process for candidate members in the Balkan region — Albania, Macedonia, Montenegro and Serbia.
Biden’s visit comes while the debate in Washington about whether to admit Syrian refugees has intensified, following a series of attacks in Paris by the Islamic State that left 130 dead and hundreds wounded.
The U.S. House of Representatives has approved a measure that, if passed, would require refugees from Syria and Iraq, although the White House contends the additional restrictions would effectively block people from those countries.
In Europe, the refugee crisis has become a source of tension among the countries on the migrant corridor — Greece, Macedonia, Serbia, Croatia and Slovenia. It has also presented a major political and security challenge for those countries.
At least two of the militants involved in the November 13 Paris attacks had passed through Greece, apparently posing as asylum-seekers.
Before arriving at the summit, Biden met with Croatian Prime Minister Zoran Milanovic and the President of the European Council, Donald Tusk.
Also in attendance at the summit are the leaders of Albania, Bosnia and Herzegovina, Kosovo, Macedonia and Serbia.
The annual gathering, held regularly since 2013, brings together presidents of all the countries of the region to promote cooperation and European integration.
The summits are usually hosted by Slovenia or Croatia, the only two Balkan countries that are members of the European Union.