ISTANBUL — President Recep Tayyip Erdogan said Friday that Turkey had uncovered further evidence in the killing of the Saudi journalist Jamal Khashoggi, pressing Saudi Arabia to reveal who gave the orders and demanding that its leaders explain what happened to Mr. Khashoggi’s body.
“There is more information,” Mr. Erdogan said at a gathering in the capital, Ankara, and suggested he might make more evidence public in the future. “But beyond all else, who gave the order?”
Turkey’s chief prosecutor officially asked Saudi Arabia to extradite 18 Saudis to Turkey to face charges of deliberate murder in the death of Mr. Khashoggi, Turkish media reported on Friday.
Mr. Khashoggi’s Turkish fiancée, Hatice Cengiz, said in a television interview on Friday that he had been relaxed and hopeful when he entered the Saudi Consulate in Istanbul on Oct. 2 to pick up a document that would allow them to marry. He was killed inside the consulate by a team of men from Saudi Arabia.
In an emotional interview that lasted more than an hour — her first television interview since his death — Ms. Cengiz described how she met and became engaged to Mr. Khashoggi, a critic of the kingdom’s leadership who wrote opinion pieces for The Washington Post, and how she put out the alarm when he did not emerge from the consulate.
His first meeting at the consulate several days earlier had been courteous, so he had few qualms going back, she said. “He did not hesitate at all.”
As hours passed and Mr. Khashoggi did not reappear, Ms. Cengiz said, she thought he was enjoying chatting with the consular staff. It was only when she realized the consulate had closed for the day that she felt a great feeling of dread and asked the guards where he was.
“It never occurred to me something like that would be done to a person like Jamal Khashoggi, who was embraced by the world, who spent his life working for his country to develop, to improve; a patriot, a nationalist, who never ever did any harm to anyone,” she said.
After weeks of insisting that Mr. Khashoggi had left the building alive, Saudi Arabia buckled under pressure from Turkey and acknowledged a week ago that he was killed, though officials insisted that his death had been an accident. The kingdom’s official story changed yet again on Thursday, when a state prosecutor said the killing had been premeditated.
The nature of the killing of Mr. Khashoggi has led many Western analysts, intelligence officials and elected leaders to suggest that it could not have been carried out without the approval of the Saudi crown prince, Mohammed bin Salman, the country’s de facto ruler and a crucial ally of the White House. Saudi Arabia has insisted that no one high in the royal family knew of the operation in advance or sanctioned it, though it has acknowledged that high-ranking aides close to the crown prince were involved.
Pushing back against Western calls to cut off arms sales or impose other sanctions, Saudi Arabia on Friday tacitly threatened that it could look instead to support from Moscow.
King Salman of Saudi Arabia spoke by telephone with President Vladimir V. Putin of Russia about the Khashoggi case on Thursday, according to statements from both governments. On Friday, a Kremlin spokesman expressed confidence in the official Saudi investigation and account of the case — remarks that were extensively covered by Russian and Saudi news media.
“There is no reason that would lead anyone not to believe Saudi Arabia’s announcements,” the spokesman, Dmitry Peskov, said.
“We have heard the royal family’s statement condemning this murder,” he said. “But everything else comes down to the investigations the royal family ordered, and we support all of it.”
The manager of a Russian government investment fund, Kirill Dmitriev, was the only European government official to play a high-profile role in the Saudi investment conference hosted this week by Prince Mohammed. Many American and European officials and businessmen dropped out of the event because of the uproar over Mr. Khashoggi’s death.
The C.I.A. director, Gina Haspel, visited Turkey this week and, according to Turkish pro-government newspapers, was presented with evidence gathered by Turkish investigators, including audio recordings of the killing.
Ms. Cengiz said she had received telephone calls from both President Trump and Secretary of State Mike Pompeo but drew little comfort from them. Mr. Trump’s invitation to visit the White House was “a sentence uttered to earn the sympathy of the public,” she said.
Mr. Erdogan said Friday that Turkey had shared evidence with those who had asked to see it but had retained the original material. Those who have seen the evidence were “surprised,” he added.
Mr. Erdogan said the killer was among the 15 Saudi agents who traveled to Turkey hours before Mr. Khashoggi arrived at the Saudi Consulate.
“Actually, the perpetrator is certain,” Mr. Erdogan said. “And something else comes up, who is the one giving the orders? On whose order did those 15 come to Istanbul on Friday? The authorities should explain this.”
He added: “And of course, we have other information and documents in our hands. You will collect the harvest when the sun rises. It is not meaningful to rush for now.”
The Turkish leader said that King Salman and Prince Mohammed had each told him in telephone calls that they had arrested 18 people involved in the crime — the 15 who traveled to Turkey and three others.
Mr. Erdogan also demanded that the Saudi leaders reveal the location of Mr. Khashoggi’s body. “You should show us the body,” he said. “If you cannot make them talk — the incident happened in Istanbul, at the consulate in Istanbul — then give them to us and we will put them on trial.”
Mr. Erdogan said the Saudi chief prosecutor would travel to Turkey on Sunday to meet with the chief prosecutor of Istanbul, who is leading the Turkish investigation.
“They will have a meeting and we will see the conclusion,” he said.
Ms. Cengiz echoed his demand. “My expectation is the same as the president,” she said. “From the bottom to the top I want to see everyone punished.”