Officials have repeatedly distanced Crown Prince Mohammed bin Salman from the event, though experts have said the "sensitive" plot would have been an order that " only the most senior" Saudi officials, like the Crown Prince, could approve of.
"We must reveal the identities of the puppet masters behind Khashoggi's killing", Erdogan wrote adding that Turkey has "moved heaven and earth to shed light on all aspects of this case".
"According to the latest information we have, the reason they cut up the body is it was easier to dissolve it", said Aktay, an adviser to President Erdogan who was close to Khashoggi.
When questioned about the possible involvement of MBS in an interview with the Wall Street Journal, Trump said, "Well, the prince is running things over there more so at this stage".
Khashoggi, a Washington Post columnist critical of the Saudi government and its de facto ruler Crown Prince Mohammed bin Salman, disappeared after he entered the Saudi consulate in Istanbul on October 2.
"Today I am inviting the global community to take serious and practical steps to reveal the truth and to prosecute those involved in a court of law".
In an op-ed published on Friday in several news outlets including Le Monde and The Washington Post, Ms Cengiz urged the global community to "bring the perpetrators to justice", adding that "the United States should be leading the way". She termed the Trump administration "devoid of moral foundation".
In addition to marking one month since Khashoggi's death, today is also the International Day to End Impunity for Crimes against Journalists, as declared by the United Nations.
The top USA diplomat has previously said the killing "violates the norms of worldwide law".
While insisting the United States did not condone Khashoggi's killing, the top USA diplomat said the United States had "deep and long-term strategic relationships" with Saudi Arabia and "we intend to make sure that those relationships remain intact".
Turkey's justice minister has meanwhile renewed a call for Saudi Arabia to cooperate in the investigation into the killing, saying "no one can escape responsibility".
The Saudi government initially insisted Khashoggi had left the consulate and later that he had died in an unplanned "rogue operation".
Mr Hashem and his family joined a crowd of people who attended a candle-lit vigil for his friend outside the Saudi Arabian Embassy in Dublin last night.
Other lawmakers urged the United States not to forsake justice for Khashoggi, in the interest of preserving trade interests with Saudi Arabia.
The official said investigators do not believe Saudi Arabia's official story on what happened to the body.
Khalid bin Ahmad tweeted that "despite the ongoing dispute, (Netanyahu) has taken a clear position on the importance of stability in the region and Saudi Arabia's role in consolidating that stability".