The Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization, CTBTO Preparatory Commission or CTBTO Prep Com is an international organization based in Vienna, Austria, that is tasked with preparing the activities of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO). The organization was established by the states that signed the Comprehensive Nuclear-Test-Ban Treaty (CTBT) in 1996. Its main purpose is twofold: to promote the entry into force of the CTBT, which bans all nuclear explosions, and to establish a global verification regime to ensure that all nuclear tests are detected.