Related Rule
New Zealand
Practice Relating to Rule 71. Weapons That Are by Nature Indiscriminate
New Zealand’s Military Manual (1992) states: “Weapons which cannot be directed at military objectives or the effects of which cannot be limited are prohibited.” 
New Zealand, Interim Law of Armed Conflict Manual, DM 112, New Zealand Defence Force, Headquarters, Directorate of Legal Services, Wellington, November 1992, § 509(4).
Under New Zealand’s International Crimes and ICC Act (2000), war crimes include the crimes defined in Article 8(2)(b)(xx) of the 1998 ICC Statute. 
New Zealand, International Crimes and ICC Act, 2000, Section 11(2).
In its written statement submitted to the ICJ in the Nuclear Weapons case in 1995, New Zealand stated:
In general, international humanitarian law bears on the threat or use of nuclear weapons as it does of other weapons … The general application of international humanitarian law to the use of nuclear weapons has also been specifically acknowledged by nuclear-weapon States. 
New Zealand, Written statement submitted to the ICJ, Nuclear Weapons case, 20 June 1995, §§ 63 and 66.
Among the customary law rules applicable to the use of nuclear weapons, New Zealand further stated: “It is prohibited to use indiscriminate methods and means of warfare which do not distinguish between combatants and civilians and other non-combatants.” 
New Zealand, Written statement submitted to the ICJ, Nuclear Weapons case, 20 June 1995, § 71.