U.S. Vice-President Joe Biden on Wednesday met with European Council President Donald Tusk and Slovenia's President Borut Pahor in Zagreb which was hosting a summit meeting of heads of state from former Yugoslav countries plus Albania within the Brdo-Brijuni Process.
The three top officials did not address the press after they met in a Zagreb hotel.
Biden and Tusk were guests at the summit, organised by Croatian President Kolinda Grabar-Kitarovic and her Slovenian counterpart Pahor.
Before the formal beginning of the summit at noon, Biden is to hold talks with Croatian Prime Minister Zoran Milanovic.
The Brdo-Brijuni Process was launched in 2013 by Slovenia and Croatia.
The Zagreb summit is taking place against a backdrop of the refugee crisis which has been affecting the countries along the Balkan migrant route for some time.
Croatia and Slovenia do not want the refugee crisis to overshadow other issues in the neighbourhood: internal developments in Montenegro where the pro-Serb Opposition opposes the country's NATO membership bid, unsolved relations between Serbia and Kosovo, and the Islamisation of Albanians in Kosovo, Macedonia and Albania, who are mainly moderate Sunnis and traditional secularists.