Cities Alliance is the global partnership supporting cities to deliver sustainable development. As global populations and urban economies expand, managing cities and providing opportunities for all citizens is essential to national prosperity, international progress, and stability. Most solutions are well known: Clear and consistent national policies, strong and stable institutions, accountable and well-resourced local governments, universal access to essential services, an inclusive approach to development, and well-informed and engaged citizens. However, most rapidly-urbanising cities have neither the resources nor the authority to deliver their mandates. To help cities of all sizes achieve these goals, the Cities Alliance promotes long-term programmatic approaches that support national and local governments to develop appropriate policy frameworks, strengthen local skills and capacity, undertake strategic city planning, and facilitate investment.