Actually, all large nuclear weapons states have agreed to do that, they just ignore their treaty obligations in perpetuity. NPT: "Article VI Each of the Part

Actually, all large nuclear weapons states have agreed to do that, they just ignore their treaty obligations in perpetuity. NPT: "Article VI Each of the Parties to the Treaty undertakes to pursue negotiations in good faith on effective measures relating to cessation of the nuclear arms race at an early date and to nuclear disarmament, and on a treaty on general and complete disarmament under strict and effective international control."