Trump on Saturday said the U.S. had selected 52 important sites in Iran that it was willing to strike, including cultural landmarks, warning Iran not to retaliate for the killing. (Under international law, purposely destroying a nation’s cultural sites could be considered a war crime.) Iran, for its part, has vowed to respond to the assassination in a “crushing and powerful manner” and said Sunday it would end all remaining commitments to limit nuclear fuel production as part of the Iran nuclear deal.

This story has been updated with a response from the Iranian mission to the U.N.