CNBC's Leonie Kidd reports that President Donald Trump has issued an ultimatum to Iran to reopen the Strait of Hormuz within 48 hours. Iran responded by threatening to target U.S. infrastructure, energy and desalination facilities, and financial entities supporting the US military budget. The situation has caused confusion in the markets, with some stocks markets selling off while oil surged before turning negative. British Prime Minister Keir Starmer is set to chair an emergency meeting to discuss the economic fallout of the Iran war.