A/RES/58/56 hand in hand and that there is a genuine need for a systematic and progressive process of nuclear disarmament; 3. Welcomes and encourages the efforts to establish new nuclear-weapon-free zones in different parts of the world on the basis of agreements or arrangements freely arrived at among the States of the regions concerned, which is an effective measure for limiting the further spread of nuclear weapons geographically and contributes to the cause of nuclear disarmament; Recognizes that there is a genuine need to diminish the role of nuclear 4. weapons in strategic doctrines and security policies to minimize the risk that these weapons will ever be used and to facilitate the process of their total elimination; Urges the nuclear-weapon States to stop immediately the qualitative 5. improvement, development, production and stockpiling of nuclear warheads and their delivery systems; Also urges the nuclear-weapon States, as an interim measure, to de-alert 6. and deactivate immediately their nuclear weapons and to take other concrete measures to reduce further the operational status of their nuclear-weapon systems; Reiterates its call upon the nuclear-weapon States to undertake the 7. step-by-step reduction of the nuclear threat and to carry out effective nuclear disarmament measures with a view to achieving the total elimination of these weapons; Calls upon the nuclear-weapon States, pending the achievement of the 8. total elimination of nuclear weapons, to agree on an internationally and legally binding instrument on a joint undertaking not to be the first to use nuclear weapons, and calls upon all States to conclude an internationally and legally binding instrument on security assurances of non-use and non-threat of use of nuclear weapons against non-nuclear-weapon States; Urges the nuclear-weapon States to commence plurilateral negotiations 9. among themselves at an appropriate stage on further deep reductions of nuclear weapons as an effective measure of nuclear disarmament; 10. Underlines the importance of applying the principle of irreversibility to the process of nuclear disarmament, nuclear and other related arms control and reduction measures; 11. Underscores the importance of the unequivocal undertaking by the nuclear-weapon States, in the Final Document of the Review Conference of the Parties to the Treaty on the Non-Proliferation of Nuclear Weapons, held in New York from 24 April to 19 May 2000, to accomplish the total elimination of their nuclear arsenals leading to nuclear disarmament, to which all States parties are committed under article VI of the Treaty, 15 and the reaffirmation by the States parties that the total elimination of nuclear weapons is the only absolute guarantee against the use or threat of use of nuclear weapons; 16 _______________ 15 2000 Review Conference of the Parties to the Treaty on the Non-Proliferation of Nuclear Weapons, Final Document, vol. I (NPT/CONF.2000/28 (Parts I and II)), part I, section entitled “Article VI and eighth to twelfth preambular paragraphs”, para. 15:6. 16 Ibid., section entitled “Article VII and the security of non-nuclear-weapon States”, para. 2. 4