A woman holds a portrait of missing journalist and Riyadh critic Jamal Khashoggi reading "Jamal Khashoggi is missing since October 2" during a demonstration in front of the Saudi Arabian consulate on October 9, 2018 in Istanbul. (Photo: Xinhua/AFP)

The United Nations on Wednesday expressed extreme concern about the fate of Jamal Khashoggi, the Saudi journalist who disappeared on Oct. 2 in Turkey.

"We remain extremely concerned about the fate of Jamal Khashoggi," said Stephane Dujarric, UN secretary-general's spokesperson.

"What our human rights colleagues called for is for the Turkish and Saudi authorities to cooperate on an investigation. We look forward to having more information on this case," he told a daily press briefing.

The United Nations is following the issue closely, he said.

UN Secretary-General Antonio Guterres has not personally intervened, said Dujarric, noting that the United Nations is not participating in the investigation.

Khashoggi went missing after he was seen entering the Saudi consulate in Istanbul last week.