WASHINGTON, June 9 (Reuters) - President Donald Trump on Tuesday said Iran shot down a U.S. Apache helicopter that was patrolling the Strait of Hormuz overnight and vowed to respond, but gave no other details. "I have just been informed by our Great Military that last night the Iranians shot down one of our highly sophisticated Apache Helicopters while patrolling over the Strait of Hormuz," Trump wrote in a social media post.