Turkish sources believe he was tortured, killed and dismembered.
The case surrounding the missing Washington Post columnist who disappeared after entering a Saudi consulate in Istanbul, Turkey, raised more concerns in the USA after mounting evidence suggested he was murdered during the visit. His fiancee and friends have said he did not leave the building.
CCTV released by Turkish TV showed a man believed to be Mr Khashoggi enter the consulate as well as a vehicle entering and leaving the building after he went inside. "All the related developments, ins and outs from Turkey, have been put under the spotlight", Erdoğan added. "Is it possible not to have camera systems at a consulate or an embassy?"
Reporters Without Borders said in a statement that between 25 and 30 professional and non-professional journalists are now detained in Saudi Arabia.
Corker spoke with reporters after the letter was released, and he emphasized that senators "specifically said it included the highest members of the regime" and could "absolutely" lead to USA sanctions targeting the Saudi Crown Prince, Mohammad bin Salman Al Saud.
The wealthy former government insider had been living in the U.S.in self-imposed exile. Bob Corker, who as chairman of the Senate Foreign Relations Committee has reviewed US intelligence on the case, said it was likely that Khashoggi was killed the day he walked into the consulate.
"It is not right to draw conclusions based on guesses, however we are concerned".
Asked in a telephone interview with Fox News Channel late on Wednesday whether Saudis were responsible for Khashoggi's disappearance or death, Trump said: "I guess you would have to say so far it's looking a little bit like that and we're going to have to see".
US President Donald Trump increased pressure on Saudi Arabia on Wednesday to provide information on what happened to missing Saudi journalist Jamal Khashoggi and said he wanted to get the bottom of what he called "a very serious situation". But after three hours I was overcome with fear and concern.
Later on Wednesday, almost a quarter of the Senate's members wrote a letter to Trump that triggered a USA investigation into the case that could result in sanctions against individual Saudis under a US human rights law. President Trump needs to raise this case immediately with Saudi Arabia and Turkey and demand answers. This is what this is meant to do, to send a strong message from us. He had been living in the U.S. state of Virginia.
"There is a delay over the Manbij deal".
Stakes are high in the relationship between the United States and Saudi Arabia, and Mr Trump is one of many Western leaders to stand by the kingdom's young leader Mohammed bin Salman.
Indication of those stakes came within four months of Trump taking office, when Saudi Arabia became his first destination on a presidential trip and he announced $110 billion in proposed arms sales. Both countries conducted separate coordinated patrols in the region between areas liberated by Turkey's Operation Euphrates Shield and Manbij, according to Turkish officials.