This paper presents a multi-resolution navigation algorithm for mobile robots operating as a single agent in unknown and complex environments. The algorithm seamlessly integrates the concepts of local navigation and global navigation, and enables adaptive decision-making based on the sensory information. The algorithm guarantees complete coverage of the search area and does not suffer from the local minima problem that is commonly encountered in potential field-based methods. The efficacy of the algorithm is validated on a high-fidelity Player/Stage simulator. Potential applications include humanitarian de-mining, hazard detection and floor-cleaning tasks.