Abstract: As a self-proclaimed 'IT Power Nation', Korea has incorporated information technology at the core of its vision for future development. Already, "ubiquitous eco-cities", most notably Songdo and Sejong City, have been master-planned by the Korean national government and are well under construction as sustainable smart cities of the future. These u-cities are defined as intelligent eco-friendly cities using advanced technologies to enhance the citizens' quality of life and city competitiveness. At the municipal level, Seoul, Korea's capital of more than 600 years of history, has adopted 'Smart Seoul' as a slogan since 2011. Interestingly, however, Seoul's mayor emphasizes communication and sharing as major aspects characterizing a smart city. In view of these different approaches, it is pertinent to question the definitions for these u-cities/smart cities and to examine the extent of their commonality as shown in relevant government initiatives and statements. The aim of this paper is to shed light on what is meant to be a smart and green city by critically examining the underlying premises from varying government perspectives. Using Songdo, Sejong City and Seoul as three case studies, the paper focuses, firstly, on the nexus of u-city and smart city definitions, and, secondly, highlights the differing government discourses imbedded in their social, economic and environmental policies. Ultimately, the paper calls for a more integrated understanding and vision in government discourses regarding the smart city.