“Guterres also said the U.S. and Israeli airstrikes violated international law, including the UN Charter. Waltz countered by saying the United States is “taking lawful actions,” adding that Iran “cannot have a nuclear weapon.”
Iravani said during the meeting that the strikes killed Iranian civilians, referring to the action as a war crime”
https://thehill.com/policy/international/5760983-us-iran-un-security-council/