President Donald Trump said Saudi authorities staged the “worst cover-up ever” in the killing of prominent journalist Jamal Khashoggi this month, as the United States vowed to revoke visas of some believed to be responsible. Trump spoke hours after Turkey’s president, Tayyip Erdogan, dismissed Saudi efforts to blame Khashoggi’s death on rogue operatives. Erdogan urged Riyadh to search “from top to bottom” to uncover those behind Khashoggi’s death in the Saudi consulate in Istanbul on October 2, an incident that sparked global outrage and strained relations between Riyadh and Washington.