US Secretary of State Mike Pompeo has arrived in Riyadh for talks with Saudi Arabia's King Salman and Crown Prince Mohammed bin Salman over the disappearance of journalist Jamal Khashoggi.

Saudi Arabia is preparing to acknowledge that Khashoggi was killed at the Saudi consulate in Istanbul, Turkey, during an interrogation that went wrong, sources have told CNN.

His family called for an independent, international commission to investigate his disappearance. Khashoggi, a Washington Post columnist, was last seen in public when he entered the consulate on October 2 to obtain papers that would have allowed him to marry his Turkish fiancée.

Turkish authorities have said he was killed at the consulate. Saudi Arabia has previously insisted he left the building the same afternoon, but have provided no evidence to support the claim.

His fiancée, Hatice Cengiz, waited outside the consulate and says she did not see him re-emerge.

President Donald Trump spoke with King Salman on Monday, after which he floated the possibility that Khashoggi died during an unauthorized operation. “It sounded to me like maybe these could have been rogue killers, who knows,” Trump told reporters.

Trump's comments may be a sign that Washington is preparing to accept Saudi Arabia's efforts to distance its leaders from whatever fate befell Khashoggi at its Istanbul consulate.

Sources told CNN that the Saudis are preparing a report that will acknowledge that the death of Khashoggi, a former Saudi royal insider who became a critic of Crown Prince Mohammed bin Salman, was the result of an interrogation that went wrong.

The sources said the interrogation was intended to lead to his enforced return to Saudi Arabia. One source said the report will likely conclude that the operation was carried out without clearance and transparency and that those involved will be held responsible.

A source acknowledged that the report was still being prepared and cautioned that things could change.

If Riyadh goes public with its new explanation, it would require a reversal of its previous claim that Khashoggi had left the consulate alive.

Saudi Arabia has been under intense international pressure to explain Khashoggi's apparent death.

The affair has created a diplomatic rift between Saudi Arabia and the West and led to international firms pulling out of a high-profile summit in Riyadh.

Trump dispatched Pompeo shortly after the Monday call with King Salman. He was undertaking a flurry of engagements with top officials in Saudi Arabia on Tuesday. He met King Salman in the morning and was due to meet the Crown Prince later.