National parliaments play a substantial role in achieving the Initiative’s objectives. They help improve the legislative framework and increase the Initiative’s visibility for citizens and the business community. Parliamentary contribution is essential in securing support for the Initiative’s goals and priorities - from enhancing digital and energy connectivity, to upgrading road and rail infrastructure (including their potential dual-use), and contributing to overall sustainable development of regional economies. On top of that, strengthening the parliamentary dimension of the Initiative can support the goals of the EU enlargement policy, since both participating EU Member States and EU candidate countries are continuously encouraged to engage in concrete cooperation.
As responsible partners to the executive branch, parliaments ensure continuity beyond electoral cycles and anchor strategic initiatives in democratic legitimacy. Parliaments have a crucial role in translating political goals and programmes into lasting legal frameworks, while also helping secure funding for key projects through adopting national budgets.
During the first decade of the Initiative, two parliamentary forums were held — in Tallinn on 3 June 2021 and in Riga on 20–21 June 2022. Both highlighted the importance of parliaments and parliamentary diplomacy in achieving 3SI objectives and increasing public visibility.
To strengthen the strategic significance and democratic legitimacy of the Initiative in its second decade, the 3SI’s objectives and benefits must be further advanced through meaningful and strategic parliamentary action. In a world shaped by uncertainty, technological rivalry, and economic competition, ensuring responsible parliamentary engagement and structured cooperation with the executive branch is of paramount importance
Against this background, the Croatian Parliament will host the Three Seas Initiative Parliamentary Summit in Zagreb on 24–25 March 2026. This open forum will provide participating parliaments with a concrete opportunity to contribute to the Initiative’s development. In addition, the outcomes and deliberations of the Parliamentary Summit will help inform the discussions at the 3SI’s Summit of the Heads of State or Government in Dubrovnik, on 28-29 April 2026.
The upcoming Parliamentary Summit is not only a timely opportunity to upgrade this collaboration and further advance the Initiative’s goals, but also a welcome reminder that legislators must remain active, responsible, and forward-looking partners in the Initiative’s continued development.