A US official warned Friday that Iran would face “cataclysmic” consequences and derail momentum toward a Gaza truce if it strikes Israel in response to the killing of a top Hamas official. The United States “would encourage the Iranians — and I know many are — not to move down that road, because the consequences could be quite cataclysmic, particularly for Iran,” a senior US official told reporters on customary condition of anonymity. President Joe Biden earlier Friday said that a ceasefire in the 10-month Gaza war was closer than ever after two days of talks in Qatar at which US mediators p…