King Salman of Saudi Arabia (L) and Turkish President Tayyip Erdogan spoke by telephone on Sunday evening and discussed the investigation into the disappearance of dissident Saudi journalist Jamal Khashoggi.
Turkish officials believe Mr Khashoggi was murdered in the consulate by Saudi agents almost two weeks ago but Riyadh has always strongly denied this. "Who knows?" Trump told reporters at the White House.
Mr Trump previously warned of "severe punishment" against Saudi Arabia if Mr Khashoggi was killed in the embassy.
The New York Times is also citing a person familiar with the Saudi plans, who says the Saudi government is preparing a scenario that would protect Prince Mohammed Bin Salman from blame. Trump added the United States "would be very upset and angry if that were the case". USA intelligence officials have reported they are certain the interference took place in an effort to hurt Hillary Clinton's campaign. Saudi officials have been in and out of the building since Khashoggi's disappearance October 2 without being stopped.
Saudi Arabia has launched an internal investigation into the episode after an instruction from King Salman, father of the crown prince, Mohamed bin Salman.
Saudi Arabia has denied the claims.
Concern over Khashoggi's disappearance has prompted media organizations and a growing number of guests to pull out of a "Davos in the Desert" investment conference set for October 23-25, which has become the biggest show for investors to promote Prince Mohammed's reform vision.
In a sign of possible tactical tensions within the kingdom, Saudi officials threatened reprisals against any country that imposes sanctions on Riyadh. Khashoggi's body was reportedly dismembered and smuggled out of the consulate building.
Trump has been facing increasing pressure from lawmakers who are asking him to hold Saudi Arabia to account if the country was behind Khashoggi's abduction or killing.
The latest moves come as more leading business figures say they will not attend a major investment conference in Riyadh later this month. The statement did not elaborate, but a Saudi-owned satellite channel later suggested the world's largest oil exporter could wield that production as a weapon against America.
Other executives such as Ford Motor Chairman Bill Ford and Uber Chief Executive Dara Khosrowshahi also won't attend the conference, according to the Wall Street Journal.
The person said Prince Mohammed had approved an interrogation or rendition of Mr. Khashoggi back to Saudi Arabia. The Arab News published a front-page editorial by Dubai-based real-estate tycoon Khalaf al-Habtoor that urged Gulf Arab nations to boycott global firms now backing out of the investment conference later this month.
Saudi Arabia has angrily rejected any suggestion it was involved in interrogating Khashoggi, who had visited the consulate on a planned trip in relation to his forthcoming marriage.