Recep Tayyip Erdogan has said he will "go into detail" about a case that has shocked the world and raised suspicions that a Saudi hit squad planned Khashoggi's killing at the country's consulate in Istanbul on 2 October and then attempted to cover it up.
Top Turkish officials have said they would clarify exactly what happened to Khashoggi as international pressure on the kingdom intensifies.
After initially denying any knowledge of Khashoggi's fate, the kingdom gave a new story on Saturday, saying he died in a "fistfight".
A diplomatic vehicle belonging to the Saudi consulate was discovered abandoned on the outskirts of Istanbul, reportedly dumped days after Khashoggi was killed by a 15-man Saudi squad.
Saudi consulate car found abandoned in Istanbul, Turkish police reveal
A diplomatic vehicle belonging to the Saudi consulate has been discovered abandoned on the outskirts of Istanbul, days after the killing of journalist Jamal Khashoggi. Security sources told Turkey's state TV the vehicle was found in the Sultangazi district, some way outside the city centre.
Today Erdogan is expected to give a speech about the murder of Khashoggi around 9.30 this morning.