The comprehensive nuclear testban treaty ctbt is a multilateral treaty that bans all nuclear explosions, for both civilian and military purposes, in all environments. Ratification, accession or notification of accession has up to the present been deposited by. Afghanistan australia austria belgium bolivia botswana brazil bulgaria burma byelorussian sovietsocialistrepubliccanada central. Partial test ban treaty ptbt nuclear threat initiative. On august 5, 1963, the limited nuclear test ban treaty was signed in moscow by u. The treaty prohibited nuclear weapons tests or any other nuclear explosion in the atmosphere, in outer space, and under water. In june 1963, the test ban negotiations resumed, with compromises from all sides. Nuclear testban treaty, formally treaty banning nuclear weapons tests in the atmosphere, in outer space, and under water, treaty signed in moscow on august 5, 1963, by the united states, the soviet union, and the united kingdom that banned all tests of nuclear weapons except those conducted underground. The partial test ban treaty ptbt is the abbreviated name of the 1963 treaty banning nuclear weapon tests in the atmosphere, in outer space and under. It was adopted by the united nations general assembly on 10 september 1996 but has not entered into force, as eight specific nations have not ratified the treaty. Atmosphere, in outer space and under water to seek to achieve the discontinuance of all test explosions of. Limited test ban treaty ltbt in 1963, which bans nuclear tests in the. On august 5, 1963, the limited nuclear test ban treaty was. The test ban treaty was signed in moscow on august 5, 1963.