U.S. Secretary of State Mike Pompeo greets Turkish Foreign Minister Mevlut Cavusoglu before their meeting in Ankara, Turkey, October 17, 2018.
Officially entitled the Future Finance Initiative, the Saudi conference describes itself as an "international platform for expert-led debate between investors, innovators and governments as well as economic leaders".
The case has provoked an worldwide outcry against Saudi Arabia, the world's top oil exporter, with more media and business executives pulling out of a planned investment conference there this month.
One CNN source cautioned that the report was still being prepared and could change, while another said it will likely conclude the operation took place without clearance, and that those involved will be held responsible. "And you'll start hearing what is happening".
Turkish officials say they fear that Khashoggi, a prominent Saudi journalist who had been in living self-imposed exile in the United States, was killed and dismembered after he entered the consulate. They provided no further details.
The Saudis have maintained Khashoggi got the document he sought and left the consulate, though the only video available shows him entering but not leaving the building. Then, when this position become untenable, Trump obediently suggested after a phone call with King Salman that perhaps "rogue killers" flew to Turkey without the knowledge of the regime and murdered Khashoggi.
"The one thing we really know as a solid fact is that Khashoggi went into the consulate and he was never seen coming out again", Mr Colville said, adding that it seemed "very probable" that some crime had been committed.
The US president gave no evidence to support the theory.
"Well this is not rogue killers, this is a rogue crown prince", Graham said in a separate interview with Fox News Radio.
"Absolutely extraordinary they were able to enlist the President of the United States as their PR agent to float it".
Trump's remarks were his most robust defense yet of the Saudis, a US ally he has made central to his Mideast agenda.
The consulate itself, where Mr Khashoggi was last seen on 2 October, was searched by Turkish investigators on Monday for the first time.
Al-Harbi and Alzahrani have the same names as two people who have been identified as members of the Saudi Royal Guard, the Times said.
Hence the urgent dispatching of U.S. secretary of state for talks with the Saudi leadership.
The recording also revealed Mr Khashoggi had fingers cut off and was told to "shut up" or face being killed, Yeni Safak reported. Those bearing responsibility for his disappearance must be held to account.
The President said the King denied any knowledge of what had happened to Mr. Khashoggi, a columnist for The Washington Post who had been critical of the Crown Prince. Some US media reports said that Saudi Arabia is planning to come out with a report in which it is expected to say that the interrogation of Khashoggi went wrong and was killed in the process.