Saudi Arabia on Sunday called the killing of journalist Jamal Khashoggi at its Istanbul consulate a "huge and grave mistake," but sought to shield its powerful crown prince from the widening crisis, saying Mohammed bin Salman had not been aware, CNBC reported.

"This is a terrible mistake. This is a terrible tragedy. Our condolences go out to them. We feel their pain," Jubeir told the U.S. broadcaster Fox.

"Unfortunately, a huge and grave mistake was made and I assure them that those responsible will be held accountable for this." He said the Saudis did not know how Khashoggi, a Saudi national and U.S. resident, had been killed or where his body was. He also said Prince Mohammed was not responsible.