​A key challenge of sustainable development is to assure that achieved accomplishments are sustained in the long-term. By stipulating the notion of sustainability, the 2030 Sustainable Development Agenda emphasizes the need for a long-term perspective in development work and international relations (UN 2015). Sustainability is defined through different inter-connected domains: Environmental, social, and economic. At its essence, it means ensuring prosperity and environmental protection without compromising the ability of future generations to meet their needs (Ban Ki-moon 2015). Sustainability is the process of creating and maintaining development in a balanced fashion without harming the environment or threatening the wellbeing of people.

While the importance of and need for long-term, sustainable solutions has been widely acknowledged, how to achieve them, both globally and locally, remains an open question. In the context of the SDGs, three years after the adoption of the 2030 Agenda, countries are taking important actions to achieve the goals. In doing so, they face daunting problem of changing climate, conflict, inequality, persistent pockets of poverty and hunger, rapid urbanization, and environmental degradation. Policymakers in every country need to reflect on how societies can be made more resilient while confronting these challenges. Transitioning towards more sustainable and resilient societies requires an integrated approach, which recognizes that these challenges—and their solutions—are interrelated. In this complex environment, how can the work of the UN contribute to finding sustainable solutions and what are the main challenges faced by the different organizations in this regard? In concrete terms, how are UN organizations ensuring sustainability of their interventions (projects and programs) and which long-lasting, transformative impacts are their activities generating both locally (on the micro-level) and beyond?