Saudi King Salman and Turkish President Recep Tayyip Erdogan have spoken by telephone over the disappearance and alleged killing of Saudi writer Jamal Khashoggi.
State-run news agencies in both Saudi Arabia and Turkey acknowledged Sunday night's call.
Turkey said Erdogan "stressed forming a joint working group to probe the case."
Saudi Arabia meanwhile said King Salman thanked Erdogan "for welcoming the kingdom's proposal" for forming the working group.
The king also said Turkey and Saudi Arabia enjoy close relations and "that no one will get to undermine the strength of this relationship."
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Khashoggi disappeared Oct. 2 while visiting the Saudi Consulate in Istanbul.
Turkey fears Saudi officials killed and dismembered The Washington Post columnist. Saudi Arabia calls the allegations "baseless," but has offered no explanation for Khashoggi's whereabouts.
Saudi threats of retaliation
On Sunday, Saudi Arabia said it would retaliate to possible economic sanctions taken by other states over the case of Khashoggi, state news agency SPA reported quoting an official source.
The kingdom will respond to any measure against it with bigger measures, the source said, adding: "The Saudi economy has vital and influential roles for the global economy."
U.S. President Donald Trump said in a CBS interview on Saturday that there would be "severe punishment" for Saudi Arabia if it turns out that Khashoggi was killed in the Saudi consulate in Istanbul.
And on Wednesday, 22 U.S. senators forced a U.S. investigation of whether human rights sanctions should be imposed over the disappearance of Khashoggi.
Asked whether Saudi Crown Prince Mohammed bin Salman gave an order to kill him, Trump said "nobody knows yet, but we'll probably be able to find out." Trump added in excerpts of the "60 Minutes" interview that will air on Sunday "we would be very upset and angry if that were the case".
"We're going to get to the bottom of it and there will be severe punishment," Trump said.