Over 25,000 participants from around the world gathered in Barcelona the first week of November for the annual Smart Cities Expo to discuss innovation in robotics for mental health and aging, nature-based solutions for electricity generation and net-zero actions, circular building systems, and new financial models for products and retrofits.  U.S. agency participants included the Department of Commerce, USTDA, State, NASA, and DOD, and an increase in attendance by representatives from around the world, as well as from U.S. cities and regions, universities, and private sector organizations, underscored a growing understanding of the importance of cities in promoting innovation, sustainability goals, and climate action.  Continued U.S. attendance at this event would promote FDI in the U.S. and raise the global visibility of U.S. products and services.