Saudi Arabia says that journalist Jamal Khashoggi was murdered, blaming rogue agents for a killing that has sparked an international outcry.
Saudi Arabia has been under pressure to explain what happened to Mr Khashoggi.
He was last seen entering the Saudi consulate in Istanbul earlier this month to sort out divorce papers.
Turkish officials believe he was murdered by a team of Saudi agents inside the building.
Saudi Arabia initially said he had left the building unharmed but on Friday admitted for the first time he was dead, saying that he was killed in a fight.
That claim though met widespread scepticism.
What’s the latest from the Saudis?
In his comments, Mr al-Jubeir described the incident as murder.
“We are determined to find out all the facts. And we are determined to punish those who are responsible for this murder,” he said.
“The individuals who did this did this outside the scope of their authority,” he added. “There obviously was a tremendous mistake made, and what compounded the mistake was the attempt to try to cover up.”
He also said that they did not know where the body was, and insisted the action was not ordered by Crown Prince Mohammed bin Salman, seen as Saudi Arabia’s most influential figure.
Saudi Arabia says it has arrested 18 people, sacked two aides of Mohammed bin Salman and set up a body, under his leadership, to reform the intelligence agency following the incident.
What has been the international reaction?
On Saturday, Mr Trump said: “I’m not satisfied until we find the answer.”
But the US president said that, although sanctions were a possibility, halting an arms deal would “hurt us more than it would hurt them”.
The UK, France and Germany issued a joint statement expressing shock at the death and demanding a full explanation, saying: “Nothing can justify this killing and we condemn it in the strongest possible terms.”
The Washington Post, which published articles by Mr Khashoggi, said the Saudi government had “shamefully and repeatedly offered one lie after another”.
However, several of Saudi Arabia’s regional neighbours and allies have come out in its support.
Kuwait praised King Salman for his handling of the case, while Egypt, Bahrain and the United Arab Emirates have been among those reflecting similar praise.
Also on Sunday, Turkey’s president Recep Tayyip Erdogan said he would make a statement on the matter in parliament on Tuesday.
“We are looking for justice here and this will be revealed in all its naked truth,” he told a rally in Istanbul.
Where is the investigation now?
Although Turkey has so far stopped short of officially blaming Saudi Arabia for the killing, investigators have said they have audio and video evidence which shows Mr Khashoggi, was killed by a team of Saudi agents inside the consulate.
Police have searched the nearby Belgrad forest in Istanbul where they believe the body may have been taken and one official was hopeful its fate would be known “before long”.
Both the consulate and the residence of the Saudi consul have been searched too.
Reuters reported on Sunday it had spoken to a Saudi official who said Mr Khashoggi had died in a chokehold after resisting attempts to return him to Saudi Arabia. His body was then rolled in a rug and given to a local “co-operator” to dispose of.
A Saudi operative then reportedly donned Mr Khashoggi‘s clothes and left the consulate.
The official said Saudi statements had changed because of “false information reported internally at the time”.