FILE PHOTO: Saudi Arabia's Crown Prince Mohammed bin Salman attends a meeting with U.S. Secretary of State Mike Pompeo in Jeddah, Saudi Arabia, September 18, 2019. Mandel Ngan/Pool via REUTERS/File Photo

DUBAI (Reuters) - Saudi Arabia’s Crown Prince Mohammed bin Salman congratulated U.S. President Donald Trump on the killing of Islamic State’s leader, describing the operation as a historic step in the fight against extremism, Saudi state TV Ekhbariya reported on Tuesday.