In a September 22 address before the UN General Assembly, President Trump made two explicit threats: he threatened to use military force in Latin America in service of US interests, and he threatened annihilation for both the Iranian government and the Iranian people.
According to a Foreign Policy analysis by Anjali Dayal, the actions Trump proposed contravene international laws prohibiting war and the international humanitarian law protecting civilians in conflict. The analysis notes that the UN Charter prohibits even threats of aggression, while the laws of war, which are also part of US law, prohibit indiscriminate threats against a civilian population.
"Trump's public deliberations about who to invade and who to annihilate were themselves crimes, committed in full view of thousands of diplomats and heads of state," Dayal wrote.
The analysis points out that Trump is accustomed to asserting the primacy of force over law and anticipates no punishment. His administration is reportedly bent on shrinking the UN and dismantling the International Criminal Court (ICC), with Secretary of State Marco Rubio previously stating the US would do so "brick by brick, if necessary."