- Video report by ITV News Correspondent Ronke Phillips
Saudi Arabia has rejected any “threats” of economic sanctions or political pressure after US President Donald Trump warned of punishments if proof emerges journalist Jamal Khashoggi has been killed.
The statement carried by the state-run Saudi Press Agency on Sunday also warned the kingdom will respond to any steps taken against it.
The words did not directly acknowledge Mr Khashoggi’s disappearance, which happened October 2 when he visited the Saudi Consulate in Istanbul.
It came after the Saudi stock market plunged by nearly 7% at one point on Sunday.
Foreign Secretary Jeremy Hunt later issued a statement along with his French and German equivalents saying the nations "expect the Saudi government to provide a complete and detailed response" to the disappearance.
The statement said the nations "share the grave concern expressed by others" and "there needs to be a credible investigation to establish the truth".
It added: "We have conveyed this message directly to the Saudi authorities."
Turkish officials fear Mr Khashoggi was killed and dismembered.
International demand for the kingdom to explain the disappearance has increased, with UN Secretary General Antonio Guterres saying he wants to know the truth about what happened.
He also expressed fears that such disappearances would occur more often and become a “new normal”.
Mr Trump said on Saturday there will be severe punishment if proof emerges that Mr Khashoggi was killed in the Saudi consulate.
The Washington Post columnist, who has been missing for 11 days, had previously written critically about Saudi Crown Prince Mohammed bin Salman.
In further accusations, pro-government Turkish newspaper the Sabah, claimed officials had obtained an audio file from the journalist's Apple Watch, which had recorded his alleged killing.
The newspaper claimed authorities recovered the audio from Mr Khashoggi’s iPhone and his iCloud account, though did not provide evidence on how the Apple Watch may have synced that information.
They also alleged Saudi officials tried to delete the recordings first by incorrectly guessing Mr Khashoggi’s PIN on the watch, then later using the journalist’s finger.
The journalist had given his phones to his fiancee before entering the consulate.
Turkish officials say they believe a 15-member Saudi “assassination squad” killed Mr Khashoggi at the consulate.
A Saudi-owned satellite news channel reported the 15-man team were “tourists” in response, without providing evidence to support this claim.
They have also claimed to have video of the killing, but have not explained how they obtained it.
Turkey is yet to publish any evidence of Mr Khashoggi's suspected murder, though surveillance footage around the consulate shows a convoy of vehicles with diplomatic plates leaving the Saudi Consulate for the consul’s home in Istanbul a little under two hours after the journalist's arrival.
Saudi Arabia has reiterated that it had nothing to do with Mr Khashoggi’s disappearance.
They have not, however, explained or offered evidence of how the writer left the consulate and disappeared into Istanbul with his fiancee waiting outside.
Early on Saturday, the state-run Saudi Press Agency published a statement from Saudi Interior Minister Prince Abdulaziz bin Saud again denying the kingdom’s involvement.
This time, however, it acknowledged for the first time that Saudi Arabia was accused of killing Mr Khashoggi.
Labour Party MP Emily Thornberry wrote an opinion piece for The Observer on Sunday, stating Britain should be holding the Saudi government to account for Jamal Khashoggi's disappearance.
She also accused the Conservative government of "turning a blind eye to the country's excesses".
Foreign Secretary Hunt hit back on Twitter, claiming the government has been "robust and will continue to be on this very troubling issue".
The full joint statement Mr Hunt issued along with French foreign minister Jean-Yves Le Drian and German foreign minister Heiko Maas read:
"Defending freedom of expression and a free press and ensuring the protection of journalists are key priorities for Germany, the United Kingdom and France.
"In this spirit, light must be shed on the disappearance of Saudi journalist Jamal Khashoggi, whose family has lost contact with him since October 2nd.
"Germany, the United Kingdom and France share the grave concern expressed by others including HRVP Mogherini and UNSG Guterres, and are treating this incident with the utmost seriousness.
"There needs to be a credible investigation to establish the truth about what happened, and – if relevant – to identify those bearing responsibility for the disappearance of Jamal Khashoggi, and ensure that they are held to account.
"We encourage joint Saudi-Turkish efforts in that regard, and expect the Saudi Government to provide a complete and detailed response. We have conveyed this message directly to the Saudi authorities."