Headline: Eliciting knowledge from stakeholders to identify critical issues of the transition to climate neutrality in Greece, the Nordic Region, and the European Union

There are considerable differences in the pace and underlying motivations of the energy transition in the different geographical contexts across Europe. The European Union's commitment to climate neutrality by 2050 requires a better understanding of the energy transition in different contexts and scales to improve cooperation of involved actors. In this article, we identify critical issues and challenges of the European energy transition as perceived by stakeholders and investigate how these perceptions vary across geographical contexts. To do so, we couple a policy document analysis with research based on stakeholder engagement activities in three different scales, national (Greece), regional (Nordic Region) and continental scale (European Union). Our findings show that stakeholder perspectives on the energy transition depend on contextual factors underlying the need for policies sensitive to the different transition issues and challenges in European regions. They also reveal cross-cutting issues and challenges among the three case studies, which could lead to further improvement of the cross-country collaboration to foster the European energy transition.