A team of investigators entered the Saudi Consulate in Istanbul on Monday for what Turkish officials called a joint inspection of the building where Saudi journalist Jamal Khashoggi disappeared almost two weeks ago.
Mr Trump said King Salman of Saudi Arabia strongly denied that the kingdom had any connection to the missing journalist, whose writings were often highly critical of the ruling royal family, reports the New York Post.
Mr Pompeo was hastily dispatched to Riyadh amid signs that the current Saudi position - a flat denial that Mr Khashoggi was killed inside their consulate in Istanbul - might be about to change.
Saudi Arabia calls the allegations "baseless" and says Khashoggi left the consulate on his own, although neither Turkey nor Saudi Arabia has provided clear evidence to support its version of events. Turkish officials have said they believe he was killed and dismembered inside the consulate.
Trump said Monday that he had spoken to Saudi King Salman bin Abdulaziz Al Saud for about 20 minutes that morning and that he has denied any knowledge of Khashoggi's disappearance.
If confirmed, the CNN report marks a stark reversal of earlier statements by Saudi officials who insisted that Khashoggi, who was last seen entering the Saudi consulate in Istanbul on 2 October, left the building a short time after he arrived.
Meanwhile on Monday, a team of Turkish and Saudi investigators entered the Saudi Consulate in Istanbul, the Associated Press reported. "Now we are at the stage of collecting concrete evidence at the consulate".
Trump said King Salman added that Crown Prince Mohammed bin Salman also "had no knowledge" about Khashoggi's fate.
Asked when the public prosecutor could make an announcement, the official said: "He was instructed to work quickly". Senators from both political parties have called for sanctions against Saudis responsible for Khashoggi's disappearance.
The inspection was agreed after a Saudi delegation of a dozen officials arrived in Turkey while Saudi King Salman and Turkish President Recep Erdogan spoke on the phone yesterday. A police dog was part of the search team.
The Saudi riyal fell to its lowest in two years and its worldwide bond prices slipped over fears that foreign investment inflows could shrink amid global pressure.
Foreign capital is key to Saudi plans for economic diversification and job creation.
Sens. Marco Rubio and Jeff Flake, members of the Foreign Relations Committee, said Congress is prepared to move quickly and firmly if Trump fails to adequately respond to the October 2 disappearance of Khashoggi, a Washington Post contributor. Blackrock CEO Larry Fink and Stephen Schwarzman, the CEO of investment firm Blackstone, have also withdrawn. Prince Mohammed told Reuters a year ago that Blackstone and BlackRock Inc were planning to open offices in the kingdom.
Additionally, companies such as Google, Uber and Bloomberg have said they will not attend an upcoming finance conference in the kingdom. The Arab News published a front-page editorial by Dubai-based real-estate tycoon Khalaf al-Habtoor that urged Gulf Arab nations to boycott worldwide firms now backing out of the investment conference later this month.