Environment, through its regional nature and by the number of EU laws covering this sector, assumes a prominent role in the implementation of regional cooperation policy.

Regional cooperation is a key obligation of the Stabilisation and Association Process. The process covers the following countries: Albania, Bosnia and Herzegovina, Serbia, Montenegro and Kosovo under UN Security Council Resolution 1244. The European Commission has been the driving force in the development of the Regional Environmental Reconstruction Programme (known as REReP). This programme seeks to provide a framework in which environmental actions can be pursued at a regional level in the Balkans. Until 2009, the financing of regional activities (including REReP) was ensured by CARDS 2005. From 2009 onwards the Program (RENA) has support from the Instrument for Pre-Accession Assistance (IPA).

In 2007 the European Commission approved the Transnational Co-operation Programme “South-East Europe” for the period 2007-2013. This programme involves Community support for regions in 16 countries - Member States, candidate, potential candidate countries and third countries.

EU Strategy for the Danube region is under development (expected to be presented by the European Commission before the end of 2010). At present, the countries mainly concerned will be those covered by the Danube Cooperation Process: Germany (Baden-Württemberg and Bavaria), Austria, the Slovak Republic, the Czech Republic, Hungary, Slovenia, Croatia, Serbia, Bosnia and Herzegovina, Montenegro, Romania, Bulgaria, the Republic of Moldova and Ukraine (the regions along the Danube). Eight are Member States of the EU and six are not.

In 2008, the Regional Cooperation Council replaced the Stability Pact for South Eastern Europe as a regionally-owned and regionally-led framework for cooperation. The Commission is a member of the RCC and its board as part of the EU delegation. The work of the RCC revolves around 5 priority areas: economic and social development, infrastructure and energy, justice and home affairs, security cooperation, and building human capital. Parliamentary cooperation is an overarching theme in the RCC.

Economically, a major step forward in regional cooperation was taken with the signing of the 2006 Central European Free Trade Agreement (CEFTA 2006), amending the original CEFTA agreement following the accession of the central and eastern European countries to the EU. Current members of CEFTA 2006 are Albania, Bosnia and Herzegovina, Croatia, former Yugoslav Republic of Macedonia, Moldova, Montenegro, Serbia and Kosovo (under UNSCR 1244/99).

The Energy Community Treaty, which was signed in 2005 and entered into force in 2006, aims to establish an integrated energy market promoting energy trade in the region and integration with the EU market, as well as enhancing security of supply.

A Transport Community Treaty, modeled on the Energy Community Treaty, is currently under negotiation between the Commission and the Western Balkan countries.

Regional cooperation is also developing in a number of other sectors.