The European Union is a leader in the implementation of sustainable development objectives both in its internal and external policies. Several brand projects were initiated through which the EU offers support to the countries of the Eastern Partnership (EaP) to identify their own ways to achieve sustainability, based on the best European practices. The objective of this research is to analyze what is the specificity of the initiatives undertaken in different countries of the PaE with the support of the EU, to ensure a better governance of sustainable development, especially through the implementation of the EU4Environment project. Another research direction is to assess the impact of policies, initiatives and actions taken by EaP countries throughout the partnership period with the EU, highlighting their results, both successes and difficulties of EaP countries in terms of sustainability. The dynamics of macroeconomic indicators, international score tables, EU4Environment reports of EaP countries and OECD green growth indicators were analyzed. The research results demonstrate that EU support is largely oriented towards strengthening sustainability governance capacities and the green transformation of SMEs.