Saudi Arabia said 21 people are now in custody, with 11 indicted and referred to trial.
The Saudi public prosecutor recommended the death penalty for five people who ordered and committed the killing of Jamal Khashoggi.
The U.S. sanctioned 17 Saudi officials over the death of U.S. -based journalist Jamal Khashoggi, as the White House seeks to quell worldwide outrage over his killing while preserving its relationship with a key ally in the Middle East.
The case sparked global outcry opened the kingdom to possible worldwide sanctions and tarnished the image of Crown Prince Mohammed bin Salman.
He said that 11 suspects had been indicted and that the authorities were seeking the death penalty for five of them.
Turkish President Recep Tayyip Erdogan said that the slaying was premeditated and that the orders had come from "the highest levels of the Saudi government", without specifying exactly who was responsible.
Among those targeted for sanctions are Saud al-Qahtani, who was one of the crown prince's closest aides, and Mohammed al-Otaibi, the diplomat in charge of the Saudi Consulate in Istanbul where Khashoggi was killed October 2. On Thursday, Turkish Foreign Minister Mevlut Cavusoglu said that some of the latest Saudi statements about the killing were not "satisfactory".
Treasury Secretary Steve Mnuchin says the United States will continue investigating to determine whether others were also responsible for Khashoggi's death.
Prince Mohammed has denied any role in the murder, describing it as a "heinous crime that can not be justified" and vowing that "justice will prevail".
Turkey has previously called for an investigation into reports the body was dissolved in acid.
Turkish officials have complained repeatedly about Saudi Arabia's refusal to identify the collaborator and said they suspect that such a person does not exist.
The US Treasury Department has designated 17 Saudi Arabians for involvement in the killing of Saudi journalist Jamal Khashoggi, imposing sanctions that freeze any assets under US jurisdiction and prohibit Americans from dealings with them.
"His royal highness the crown prince has nothing to do with this issue", Jubeir he told reporters in Riyadh.
Last month, two intelligence sources said that Qahtani gave orders over Skype to Khashoggi's killers. Gen Assiri and Mr Qahtani have also been sacked over the incident.
Riyadh initially denied any knowledge of Khashoggi's disappearance, then offered contradictory explanations including that he was killed in a rogue operation.
Al-Assiri, believed to have been a close confidant of Prince Mohammed, and former royal court adviser al-Qahtani are accused of planning and ordering Khashoggi's forced return to Saudi Arabia.
Shalaan told reporters in Riyadh that Khashoggi's "presence overseas represented a threat to the Saudi kingdom". The adviser believed that Khashoggi had been co-opted by organizations and countries hostile to the kingdom "and his presence overseas represented a danger to national security", the prosecutor said.
The public prosecutor, the statement went on, has requested "that the Turkish authorities sign a special cooperation mechanism specific to this case with a view to providing them with results of the investigation, pursuant to Saudi law, and obtaining the relevant evidence and information now in possession of the Turkish authorities". He said Riyadh asked Ankara to share witness testimonies and hand over Khashoggi's phones.