An international legal regime that comprehensively governs the exploitation of space resources is currently missing; nevertheless, the United States has enacted legislation specifically disciplining this activity. The US Space Act gives rise to the question of whether a State, through national law, can unilaterally discipline a specific use of commons over which States have joint stewardship, especially if, at the international level, such a use is not comprehensively disciplined and lacks consensus. This paper does not have the ambition to resolve the persisting academic debate surrounding the interpretation of international space law regarding the appropriation and utilization of space resources. Rather, it attempts to provide legal support for the concept that the international community is the sole subject in the position to further specify the rules to govern the use of outer space and celestial bodies, including of the resources thereof. In doing so, the US Space Act is analyzed in light of the key principles of the Outer Space Treaty relevant to the exploration and use of space resources. These principles are further subjected to critical analysis, the outcome of which is assessed against the Moon Agreement provisions. In its conclusion, the paper explores which legal steps States could possibly undertake to ensure a smooth and prosperous development of the space mining industry.