Given the state of the climate emergency, European Union (EU) cities must find innovative ways to achieve a sustainable and decarbonised urban mobility trajectory. This requires integrated and cross-sectoral approaches that enable all sectors influencing such mobility to contribute to this goal. Building on the concept of the climate-connected city and drawing on an extensive empirical investigation of two Dutch cities (Rotterdam and Maastricht), this study reflects on how decarbonisation targets are integrated with other sustainability objectives across all policies and levels involved in reconfiguring mobility towards an environmentally sustainable model. The study finds that spatial development tools and processes, in combination with regulatory instruments imposing strict limits on emissions, can strengthen cross-sectoral support for the behavioural changes needed to decarbonise urban mobility. However, this integrative dynamic may be countered by local economic actors and by national and EU economic and fiscal instruments, whose narrow focus on reducing vehicle emissions and expanding road capacity forces cities to dilute their sustainable mobility policies. This suggests that in order to accelerate the decarbonisation of urban mobility, these instruments should be aligned with a broader set of sustainability goals and solutions and be combined with greater attention being given to the urban dimension into national and European transport policies.