Turkish President Recep Tayyip Erdogan has said the order to murder Jamal Khashoggi came from "the highest levels of the Saudi government", blaming the kingdom's authorities directly for the first time since the journalist's murder a month ago.
Mr Erdogan also promised to continue the pursue the killers in an opinion article published on Friday in the Washington Post, to which Khashoggi was a contributor.
However, the Turkish president said he did "not believe for a second" that King Salman was to blame for the death.
"I have no reason to believe that his murder reflected Saudi Arabia’s official policy," Mr Erdogan wrote. "In this sense, it would be wrong to view the Khashoggi slaying as a 'problem' between two countries. Nonetheless, I must add that our friendship with Riyadh, which goes back a long time, doesn’t mean we will turn a blind eye to the premeditated murder that unfolded in front of our very eyes."
Khashoggi was a former insider in Saudi royal circles who went into self-imposed exile in the United States last year. He was killed after entering the Saudi consulate in Istanbul on October 2 for paperwork to marry his Turkish fiance. His body has yet to be recovered.
Saudi Arabia has dismissed six officials and arrested 18 people in connection with the killing, which it said was carried out without the knowledge of the country's leaders. Saudi Crown Prince Mohammed bin Salman denounced the murder as "repulsive".
Saudi chief prosecutor Saud Al Mojeb travelled to Turkey in late October to discuss the investigation, but Mr Erdogan said the Saudi authorities had "refused to answer" questions such as who ordered the assassination, the whereabouts of Khashoggi's body, and the identity of a "local collaborator" alleged to have helped dispose of it.
Saudi Arabia has also rejected Ankara's request to extradite the Saudis being held over the murder and called on a Turkish delegation to visit Saudi Arabia to present evidence.
"The killing of Khashoggi is inexplicable," Mr Erdogan wrote on Friday. "Had this atrocity taken place in the United States or elsewhere, authorities in those countries would have gotten to the bottom of what happened. It would be out of the question for us to act any other way."
The killing also strained Saudi Arabia's ties with Washington and other western allies. On Wednesday, US Secretary of State Mike Pompeo described it as a violation of international law, while France said not enough was being done to find those responsible.