A joint Saudi-Turkish team on Monday began its search of the Saudi Consulate General in Istanbul, where U.S.-based journalist Jamal Khashoggi went missing almost two weeks ago.

Quoting sources, U.S. media reported the same day that Saudi Arabia is preparing a report that will acknowledge Khashoggi's death and explain it as the result of an interrogation that went wrong.

(Investigators enter the Saudi Consulate in Istanbul)

Turkish authorities had said Khashoggi, a Washington Post columnist and prominent Saudi critic, was murdered by a team of 15 Saudi agents in the consulate on Oct. 2. Saudi Arabia has denied the claim.

U.S. President Donald Trump suggested Monday that "rogue killers" could have been behind Khashoggi's disappearance after a phone talk with Saudi King Salman over the case. Secretary of State Mike Pompeo left Washington for Riyadh to meet with the king on Trump's orders.

Trump on Sunday threatened "severe punishment" if the investigation concludes that Saudi Arabia was involved in Khashoggi's murder. Saudi Arabia responded with a statement threatening "greater action" in retaliation to any possible sanctions.