Chapter II
Crimes
Section II
War crimes
Article 11
War crimes involving the employment of prohibited methods of war
Anyone who, in the context of an international armed conflict or a non-international armed conflict:
(g) Declares or threatens, as a person with official status, that no quarter will be given;
shall be punished with a term of imprisonment of 10 to 25 years.
Denial of quarter - IAC
Denial of quarter - NIAC
EDIT.