By resolution 71/258, the General Assembly decided to convene in 2017 a United Nations conference to negotiate a legally binding instrument to prohibit nuclear weapons, leading towards their total elimination. The Assembly encouraged all Member States to participate in the Conference and decided that it shall convene in New York, under the rules of procedure of the General Assembly unless otherwise agreed by the Conference, with the participation and contribution of international organizations and civil society representatives. The Conference will be held in New York from 27 to 31 March and from 15 June to 7 July. The Conference held a one-day organizational session in New York,on 16 February 2017.
The decision to convene the Conference followed from the recommendation of the open-ended working group on taking forward multilateral disarmament negotiations, convened pursuant to resolution 70/33. The open-ended working group, chaired by Ambassador Thani Thongphakdi (Thailand), specified in its report that a legally binding instrument to prohibit nuclear weapons would establish general prohibitions and obligations as well as a political commitment to achieve and maintain a nuclear-weapon-free world. The primary mandate of the open-ended working group was to address concrete effective legal measures, legal provisions and norms that would need to be concluded to attain and maintain a world without nuclear weapons.
Source: UN website