The foreign ministers of the three countries demanded an investigation into Mr Khashoggi’s disappearance and called for a “detailed response” from Saudi Arabia.
“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,” the foreign ministers said in the joint statement.
“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.”
The statement, by UK foreign minister Jeremy Hunt, France’s Jean-Yves Le Drian and Germany’s Heiko Maas, made no mention of potential actions the countries might take.
It comes after Saudi Arabia vowed to retaliate to possible economic sanctions taken by other countries after Donald Trump warned of “severe punishment” over the disappearance of a Saudi journalist.
“The kingdom affirms its total rejection of any threats and attempts to undermine it, whether through economic sanctions, political pressure or repeating false accusations,” it said in a statement.
“The kingdom also affirms that if it is [targeted by] any action, it will respond with greater action.”
Steadfast & Glorious 🇸🇦
Demise is the outcome of these weak endeavors pic.twitter.com/WBb9yusaE6
— Foreign Ministry 🇸🇦 (@KSAmofaEN) October 14, 2018
Saudi’s ministry of foreign affairs also tweeted that it was “steadfast and glorious” in response to what it called “false accusations.” It added: ”Demise is the outcome of these weak endeavours.”
Turkish officials have said they fear Saudi agents killed and dismembered Mr Khashoggi after he entered the consulate and a Turkish newspaper has reported that Mr Khashoggi’s alleged torture and death may have been recorded on his Apple Watch.
The kingdom has called the allegations “baseless”, but has offered no evidence to show the writer ever left the consulate.
However Saudi King Salman bin Abdulaziz Al Saud adopted a more conciliatory tone in a phone call with Turkish president Tayyip Erdogan on Sunday, according to the Saudi state press agency.
The king thanked Mr Erdogan for welcoming the Saudi proposal to form a joint working group to discuss the disappearance of Mr Khashoggi and stressed the strength of the relationship between the two countries, it was reported.
Saudi Arabia also received support from Egypt, which said it was monitoring developments “with concern” and warned against the case being exploited politically.
“Egypt stresses the importance of revealing the truth of what happened in a transparent investigation,” the country’s foreign ministry said in a statement.
Saudi Arabia’s crown prince, Mohammed bin Salman, has aggressively pitched the kingdom as a destination for foreign investment, but Mr Khashoggi’s disappearance and suspicions he may have been targeted over his criticism of the crown prince have led several business leaders and media outlets to back out of an upcoming high-profile investment conference in Riyadh.
Mr Khashoggi’s fiancee said those behind his disappearance “must be held accountable and punished to the full extent of the law”.
Hatice Cengiz said Mr Khashoggi “was a patriot”. Writing in The New York Times, she said: “Jamal spoke up against oppression, but he paid for the Saudi people’s demand for freedom with his own life.”
She added: “Oppression never lasts forever. Tyrants eventually pay for their sins.”
Mr Hunt’s statement came after shadow foreign secretary, Emily Thornberry, criticised the UK’s response to Mr Khashoggi’s disappearance.
The Labour MP said there had been “nothing but pusillanimous mutterings” from Mr Hunt over the disappearance of the Saudi writer.
“He is being outdone by Donald Trump, whoever would have thought that?” she said.
“They’re playing catch-up with Donald Trump when it comes to condemnation of this and actually taking action and being prepared to stand firm.”