The US has indications that Iran is preparing to imminently launch a ballistic missile attack against Israel, a senior White House official said on Tuesday.The US is actively supporting preparations to defend Israel against this and a direct military attack on Israel by Iran would carry severe consequences for Iran, the official said.Israeli air defence systems are fully prepared for any attack from Iran but no threat has been identified at present, an Israeli military spokesperson said on Tuesday, minutes after the US warned that an attack could be imminent.Israel and its allies are…