The official said on Sunday night that a joint defense is being prepared, declining to elaborate further.
The Pentagon also said in a statement on Sunday night that "should Iran, its partners, or its proxies use this moment to target American personnel or interests in the region, the United States will take every necessary measure to defend our people."
Israel dropped 85 "bunker-buster" bombs weighing 2,000 pounds each on a residential neighborhood in Beirut’s southern suburbs on Friday, flattening at least six apartment buildings with civilians in order to assassinate Nasrallah, who was holding a meeting underground. While casualties are still being compiled, Lebanon’s public health ministry reported at least 11 people killed and 108 wounded in the attack.