Special Rapporteur Agnes Callamard, on a week-long visit to Turkey with a forensic and legal team, met Foreign Minister Mevlut Cavusoglu a day earlier.
"We have made a request to the Saudi government for access to the consulate as well as meetings with Saudi authorities here. We're waiting for their response," Callamard told Al Jazeera on Tuesday.
"To be fair the request came to them quite late so we must give them time to process our request. We are respectfully asking the authorities to give us access at some stage."
Khashoggi was murdered inside Saudi Arabia's consulate in Istanbul on October 2 last year.
US intelligence agencies believe Crown Prince Mohammed bin Salman ordered an operation to kill the Washington Post writer. Riyadh denies the prince had any involvement, alleging "rogue" Saudi elements acted on their own accord.
'No question'