The Latin American country's mission to the United Nations said Friday that Guatemala has ratified the United Nations-backed international treaty banning nuclear tests, bringing the number of states that have ratified the treaty to 156. A total of 182 out of 195 states have signed the Comprehensive Test Ban Treaty (CTBT). For the treaty to enter into force, ratification is required from the so-called Annex 2 states. Of these, China, the Democratic People's Republic of Korea (DPRK), Egypt, India, Iran, Israel, Pakistan, and the United States have yet to ratify it. Annex 2 states are the 44 countries that had participated in the negotiation of the CTBT from 1994 to 1996 and that possessed nuclear power or research reactors at the time. Latin America and the Caribbean was the first region in the world to establish a nuclear-weapon-free zone with the Treaty of Tlatelolco in 1967.