Introduction
EU agencies have been pivotal to EU governance over the last three decades, especially through their regulatory, technical, and implementation-related roles across different policy fields, with increasingly active relations with third countries through formal working arrangements, participation in networks, technical assistance, training, and capacity-building activities.This blog focuses on their engagement with the ten EU candidate states and their role in the evolving dynamics of enlargement. Its central argument is that EU agencies already provide a practical, if uneven, channel through which candidate countries can gradually become integrated into EU regulatory governance before accession. Its central argument is that EU agencies already provide a practical, if uneven, channel through which candidate countries can gradually become integrated into EU regulatory governance before accession.
Drawing on results from a 2024 survey with 24 members of the EU Agencies Network (EUAN), we show the extent of their cooperation with candidates, ranging from ad hoc exchanges to complex participation patterns. As the current geopolitical situation has brought enlargement back into focus, the EU is reassessing its strategy to ensure more effective cooperation with prospective members. While accession negotiations remain slow or stalled for most of the candidates, EU agencies have emerged as one of the key instruments for supporting regulatory alignment and institutional capacity-building. The European Union finds itself at a pivotal moment, simultaneously rethinking its internal governance and enlargement perspectives.
Current debates center on how to advance the enlargement process while simultaneously establishing mechanisms that enable candidates to participate in integration without full membership. Therefore, engagement of candidate countries with EU agencies can also be studied as a form of differentiated integration, understood here as participation in selected EU policies, structures, or regulatory frameworks without full EU membership, and a practical, still underexplored pathway for sectoral alignment, regulatory adaptation, and gradual inclusion into EU policy frameworks. r sectoral alignment, regulatory adaptation, and gradual inclusion into EU policy frameworks.
The Changing Landscape of EU Enlargement
The EU enlargement process has become increasingly complex and uneven since Croatia’s accession in 2013, the last successful entry in the Union. Although Russia’s aggression against Ukraine in 2022 brought political urgency to the enlargement process, the accession trajectories of the ten current candidates—Albania, Bosnia and Herzegovina, Georgia, Kosovo*, Moldova, Montenegro, North Macedonia, Serbia, Turkey, and Ukraine—remain fragmented. While for the Western Balkans, negotiations have advanced with Montenegro, Albania, and, to a certain extent, Serbia, others face persistent obstacles: North Macedonia, despite formal openings, Bosnia and Herzegovina in the early stages, and the Eastern Partnership candidates only recently moving onto the accession track, while negotiations with Turkey remain stalled.
EU Agencies as Instruments of Regulatory Integration
No other institutions or bodies of the Union have become as important for regulatory governance in the EU as EU agencies, while providing an opportunity for (almost full) participation by non-Member States. There are over 40 different decentralised agencies active across the policy spectrum, from transport to energy to medicine safety. EU agencies have attracted sustained scholarly attention over the past three decades, with debates focusing on their institutional design, delegated powers, accountability mechanisms, and various legal and political challenges related to their place in the EU institutional architecture.
Only in the past decade has research begun to move beyond the Union’s internal administration to examine the external dimension of agency activity, including the participation of non-EU European states. In this regard, it is possible to distinguish between three groups: the EEA/EFTA states, the post-Brexit United Kingdom, and the current ten EU membership candidates and potential candidates. The EEA/EFTA countries—Norway, Iceland, and Liechtenstein, together with Switzerland—have the most comprehensive relations with EU agencies, rooted in their broader integration into the internal market. By contrast, the UK’s withdrawal transformed it from a fully-fledged participant in all EU agencies into a third country with only limited involvement in six of them. The third group comprises the ten EU candidates and potential candidates, including long-standing candidate Turkey, the six Western Balkan candidates, and three Eastern Partnership countries. The legal basis for their engagement varies: while the Treaties contain no general provision on the creation of agencies or third-country involvement, Article 8 TEU provides a basis for developing special relationships with neighbouring countries, including through specific agreements that may extend reciprocal rights and obligations, as well as joint activities.
In addition, most founding acts of agencies provide for engagement with, and even certain forms of participation by, third countries. Various types of agreements or other instruments are concluded by different EU agencies and candidate countries, one example being the working arrangements between the European Union Aviation Safety Agency (EASA) and Serbia from 2024. Other examples include long-lasting relations between the European Environmental Agency (EEA) and the Western Balkans that have enabled candidate countries to participate in technical exchanges, training activities, and information-sharing systems. In this sense, EU agencies hold unique potential to sustain integration dynamics beyond the formal accession track, offering candidate and neighbouring states a tangible avenue for alignment as they prepare for prospective EU membership.
Insights into the engagement patterns
There are various examples of third-country engagement and/or participation in EU agencies. The motivations of the EU and third countries for these engagements are also multifold. The survey, whose results are summarily presented here, was undertaken during the period of July – September 2024 and targeted all decentralised agencies represented in the EU Agencies Network (EUAN). It focused on agencies’ engagement with ten accession candidates and potential candidates. The aim of the survey was not simply to map existing forms of cooperation, but to better understand how EU agencies themselves perceive their role in the enlargement process, and whether agency engagement is viewed as a tool for long-term accession preparation.
Forms of cooperation. By examining patterns of formal cooperation, ad hoc interaction, observer participation, and capacity-building activities, the survey sheds light on how agencies contribute—often in fragmented and informal ways—to the integration of candidate countries beyond the traditional accession framework. In addition to mapping current practices, the questionnaire sought to gather reflections on the potential for extending engagement as part of the larger efforts to integrate candidate countries into the EU policies, even without full membership in the EU. The survey in which representatives from 24 EU agencies members of (EUAN) took part provides the first cross-sectoral mapping of how candidate and potential candidate countries engage with these EU bodies. The results show a pattern of broad but uneven inclusion, with some candidates, particularly in the Western Balkans, already strongly engaged. A majority of the agencies (58%) reported having formal working arrangements in place, most often in the form of Memoranda of Understanding or Cooperation Agreements. North Macedonia, Montenegro, Albania, and Serbia appeared most often in these formal ties. Ukraine, despite its recent candidate status, was already included in seven such arrangements. Alongside these structured links, ad hoc cooperation has become widespread: 75% of agencies had organised activities such as study visits, technical assistance, training programmes, or joint workshops between 2004 and 2024 (as respondents were asked to provide insights into a two-decade period).
Depth of participation. Engagement is not limited to technical exchanges. Around 38% of the agencies grant candidate countries observer status in their management boards or scientific committees. This practice, again concentrated in the Western Balkans and Turkey, offers candidates access to deliberations, but without voting rights. Still, the purpose of cooperation varies: just under half of the respondents (46%) explicitly framed their engagement as preparatory for acquis alignment, while a third said this was not their intention, and the remainder gave mixed or inconclusive answers. Similarly, when asked whether the EEA/EFTA model provided a relevant template, responses were divided. Roughly half of the agencies viewed it as a useful point of comparison, whereas others stressed that the legal and institutional contexts of candidate countries make the model only partially applicable.
The survey also probed the possibility of candidate countries achieving membership in agencies (albeit without voting rights). Here, only three—ERA, ECDC, and Eurojust—acknowledged that their regulations would, in principle, allow such participation. More than half categorically denied this possibility, citing founding act restrictions or the need for Treaty-level changes, while the rest gave no clear position. At the same time, indirect forms of inclusion were more common. Two-thirds of agencies (16 out of 24) participate in broader EU networks, and many reported that candidate countries are already involved as participants or observers in these forums.
Constraints and limits of inclusion. Looking ahead, nearly half of the respondent agencies (11) indicated that they are planning to deepen their cooperation with candidates as preparation for internal market participation. Examples include expanding training, integrating candidates into reporting systems, and designing tailored programmes aligned with enlargement priorities. Three agencies said they had no such plans, while the rest remained silent. The findings also expose some of the more tangible limits of inclusion. Only a quarter of agencies currently involve candidate-country nationals through secondments or traineeships, constraining opportunities for knowledge transfer and personal networks. In addition, only 3 reported receiving financial contributions from candidates, with most activities funded by EU instruments such as IPA.
Taken together, these responses present a patchwork of practices: candidate countries often benefit from ad hoc arrangements and observer participation, while in some sectors formal agreements are well established. Yet staffing opportunities and financial contributions remain minimal, and legal restrictions prevent any straightforward path to agency membership, which is currently offered only to EEA countries and Turkey in two cases – the European Environmental Agency (EEA) and the European Union Drugs Agency (EUDA). The overall picture is one of important but fragmented pre-accession integration. EU agencies clearly serve as practical vehicles of EU regulatory transfer and capacity-building, but their role in enlargement remains inconsistent, dependent on individual agency mandates, and largely driven by wider EU initiatives and funding.
Conclusion: EU Agencies and the Future of Enlargement
Drawing on results from the survey with members of the EU Agencies Network (EUAN), we show the extent of their engagement with candidates, ranging from ad hoc exchanges to complex participation patterns. In this context, engagement with EU agencies offers a practical, underexamined pathway to advancing sectoral alignment, regulatory adaptation, and long-term accession preparation across all ten candidates. While EU agencies remain a constitutional puzzle in the EU legal order, their engagement with candidate countries highlights both the challenges and the opportunities of enlargement. The survey findings confirm that these agencies already function as vehicles of differentiated integration, even if in fragmented form, and their structured involvement may become indispensable for sustaining momentum in the enlargement process. At the same time, the findings raise broader questions about the future design of enlargement: whether more systematic forms of agency participation for candidate countries should be developed, and to what extent such engagement could be more explicitly embedded within the EU’s accession process. Further research could examine whether a more coordinated and transparent framework for agency–candidate cooperation would enhance regulatory alignment and the credibility of the enlargement process.
Marko Milenkovic is a principal research fellow at the Institute of Social Sciences in Belgrade, Serbia, and a visiting fellow at the European University Institute – Robert Schuman Centre. He is also an affiliated research fellow at the Center for Constitutional Studies and Democratic Development (CCSDD), part of Johns Hopkins University School of Advanced International Studies (SAIS) in Bologna.
* This designation is without prejudice to positions on status and is in line with UNSCR 1244 (1999) and the ICJ Opinion on the Kosovo declaration of independence.