Turkish sources have said previously that authorities have an audio recording purportedly documenting the murder.
On Saturday evening, leaders and heads of governments from around the world, as well as heads of global organizations, gathered for a dinner in the Orsay Museum in Paris ahead of the end of World War I centenary commemorations that are held in the French capital on Sunday.
Last month, Istanbul's chief prosecutor said that Khashoggi was strangled as soon as he entered the consulate and that his body was dismembered, in the first official comments on the case.
He again called on Saudi Arabia to provide answers as to what happened to Khashoggi and his body, which has not yet been found.
Secretary of State Mike Pompeo told Saudi Crown Prince Mohammed bin Salman on Sunday the U.S. will hold accountable all involved in the killing of a dissident Saudi journalist in a wide-ranging telephone call that also took in the conflict in Yemen. "We gave them to Saudi Arabia, to America, to the Germans, French and the English - we gave them all".
"There's no need to distort this issue, they know for certain that the killer, or the killers, is among these 15 people".
In an interview with Al-Jazeera, Nazif Karaman, the head of investigations at the Turkish Daily Sabah newspaper, cited audio recordings of Khashoggi's final words as he was being murdered in the Saudi consulate in Istanbul.
He was referring to an alleged 15-member assassination squad that Turkey believes was sent to kill Mr Khashoggi at the consulate where he had arrived to obtain papers to marry his Turkish fiancee.
But the existence of such a recording had not been officially confirmed.
The Saudis have also denied comments allegedly made by Saudi Crown Prince Mohammed bin Salman describing Khashoggi as a unsafe Islamist.
Media reports have suggested that his body could have been chemically dissolved.
Erdogan has demanded greater cooperation from Riyadh in investigating the affair amid distrust between the two nations after the Saudis' initial denials that Khashoggi was dead.
They include the killing itself and conversations pre-dating the operation which Turkey subsequently uncovered, the sources said.
During a phone call with President Donald Trump's son-in-law Jared Kushner and national security adviser John Bolton, Prince Mohammed said Khashoggi had been a member of the Muslim Brotherhood, a transnational Islamist organisation, according to the Washington Post.
Saudi Arabia now acknowledges that Khashoggi was intentionally killed in the building and says it has arrested 18 people.