A handout photo made available by the Saudi Press Agency (SPA) shows US President Donald J Trump (R), US First Lady Melania Trump (R-2), King Salman bin Abdulaziz al-Saud of Saudi Arabia (C) and Egyptian President Abdel Fattah al-Sisi (L) opening the World Center for Countering Extremist Thought in Riyadh, Saudi Arabia on May 21. President Trump is in Riyadh to attend the GCC summit.  EPA/Saudi Press Agency