(ANSA) - BUDVA (MONTENEGRO) - Environment, blue economy, and infrastructure, the enlargement of the European Union are the key themes of the 4th Adriatic-Ionian macro-region Forum (Eusair), which is going to begin Tuesday in Budva, in Montenegro. The goal of Eusair, one of the four EU macro-regions, is to face the common challenges starting from territories that share geographical features and similar problems, in order to achieve sustainable development. The Eusair Adriatic-Ionian macro-region was founded in 2014 and includes 4 EU countries (Italy, Croatia, Greece, and Slovenia) and is the only one to include the countries in the Western Balkans, which are moving towards joining the EU (Albania, Bosnia and Herzegovina, Montenegro and Serbia). Thirteen Italian regions take part in Eusair: Molise, Friuli Venezia Giulia, Emilia-Romagna, Marche, Umbria, Puglia, Sicily, Lombardy, Veneto, Basilicata, Calabria and the Autonomous Provinces of Trento and Bolzano. (ANSA).