Journalist Jamal Khashoggi, critical of Saudi policies, has been missing since October 2.

Turkey's foreign minister on Saturday accused Saudi Arabia of failing to cooperate in the probe into the disappearance of journalist Jamal Khashoggi at its consulate in Istanbul, calling on Riyadh to grant access to Turkish investigators.

"We still have not seen cooperation in order to ensure a smooth investigation and bring everything to light. We want to see this," Foreign Minister Mevlut Cavusoglu was quoted as saying by state-run Anadolu news agency.

Ankara had said that a search of the consulate had been agreed but this has yet to materialise amid reports the two sides are at odds over the conditions of entry into what is Saudi sovereign territory.

Speaking during an official visit to London, Cavusoglu said that Riyadh must let Turkish "prosecutors and experts enter the consulate" to carry out their investigation.

"Where did he go missing? There, at the consulate," the Turkish foreign minister said, adding that "talks are continuing" with Saudi officials in a bid to resolve the impasse.

Khashoggi, a Washington Post columnist who had been living in self-imposed exile in the US since late 2017, vanished on October 2 after entering the Saudi consulate in Istanbul to get paperwork for his upcoming wedding.