The European Union (EU) has positioned itself as a global leader in addressing climate change and biodiversity loss, reflecting its commitments under international frameworks such as the Paris Agreement and the Kunming Montreal Global Biodiversity Framework (KMGBF). This study evaluates the EU’s approach to mainstreaming climate and biodiversity objectives into its external financing instruments during the Multiannual Financial Framework (MFF) 2021–2027 with the aim to provide recommendations for the post-2027 period. Financial instruments under review include the Neighbourhood, Development and International Cooperation Instrument (NDICI) – Global Europe and the Instrument for Pre-accession (IPA III), as well as underlying funds such as the European Fund for Sustainable Development Plus (EFSD+). The study highlights advancements in integrating green priorities while addressing emerging concerns regarding EU international competitiveness and security; yet it identifies persistent challenges, such as aligning local ownership with environmental goals, improving the effectiveness of biodiversity financing and addressing transparency in expenditure tracking for the post-2027 period. Recommendations focus on refining methodologies for monitoring climate and biodiversity actions, strengthening the implementation of the Do No Harm (DNH) principle, enhancing sectoral exclusions to prevent funding harmful activities and leveraging global best practices to improve reporting systems. While the EU is expected to contribute to the ambitious New Collective Quantified Goal for climate finance and the KMGBF biodiversity finance targets, this study advises maintaining current financial targets due to existing constraints. Instead, it calls for reinforcing political will, fostering financial innovation and improving standardised processes to ensure EU investments align with green principles.