A man speaks on the phone outside Saudi Arabia's consulate in Istanbul on Saturday. (Petros Giannakouris/AP)

 A combative Saudi Arabia said Sunday that it would not bend to “threats” as it pushed back against growing U.S. and international pressure over allegations that it is responsible for the death of Washington Post columnist Jamal Khashoggi, warning of retaliation for any sanctions. 

The kingdom’s government is as “glorious and steadfast as ever,” and neither threatened economic measures nor the repetition of “false accusations” will hurt it, the official news agency said, even as the Saudi financial market plummeted. Censure of any kind would be met with “greater action” from Riyadh, it added, pointing out Saudi Arabia’s “vital role” in the world economy. 

But conciliatory statements from the Saudi Embassy in Washington shortly afterward indicated a leadership in disarray, as cracks showed in its long-term alliance with the United States. It is a relationship that Crown Prince Mohammed bin Salman has worked hard to further cement under President Trump, including with a high-profile visit to the United States in March. 

Trump has said “severe punishment” would follow if it is found that Saudi Arabia killed Khashoggi, last seen at 1:14 p.m. on Oct. 2 stepping through the gray metal gates to the Saudi mission, where he planned to complete paperwork for his wedding. 

In Europe on Sunday, Britain, France and Germany also expressed “grave concern” and called for a “credible investigation” of his fate and a detailed Saudi response. “We have conveyed this message directly to the Saudi authorities,” they said in a joint statement.  

Saudi leader King Salman called Turkish President Recep Tayyip Erdogan on Sunday, thanking him for welcoming the kingdom’s proposal to set up a “joint working group” to probe Khashoggi’s disappearance, a Saudi statement said.

However, Turkish officials said Sunday that Saudi Arabia appears to be using delay tactics and is interested only in presenting a facade of cooperation. 

While denying involvement, Saudi Arabia has not explained why Khashoggi has not been seen since Oct. 2, including in footage from closed-circuit television cameras that monitor surrounding streets. Turkish officials say it is because he died inside, and they have told U.S. officials that they have audio and video recordings to prove it.

The admonitions to the United States emanating from Saudi Arabia “bring into question the essential pillars that underpin U.S.-Saudi relations,” said Kristin Diwan, a scholar at the Arab Gulf States Institute in Washington. “Saudi Arabia has a strategic value to the U.S. that comes from its reliability in managing oil markets and coordinating intelligence. If it can’t be trusted for this, then all bets are off.”  

The Saudi government deployed similar tactics during quarrels in the past year with Germany and Canada, she said. “I feel like it’s hitting its limits,” she added. “It’s a big test to try this against the United States.”

After the Saudi government statement was released early Sunday, Turki Aldakhil, the general manager of the Saudi-owned al-Arabiya news network, wrote in a column that “decision-making circles within the kingdom” were considering more than 30 potential measures in response to the threat of sanctions, including pricing oil in Chinese yuan rather than the dollar and allowing Russia to build a military base on Saudi soil.  

But later Sunday, Faisal bin Farhan, a senior adviser to the Saudi Embassy in Washington, wrote on Twitter that the column “in no way reflects the thinking of the Saudi leadership.” The embassy also issued on its Twitter account what it said was a clarification of the government statement, writing that the kingdom “extends it appreciation to all, including the US administration, for refraining from jumping to conclusions on the ongoing investigation,” an apparent reference to Khashoggi’s disappearance.  

The stronger line from the White House comes after the release Friday of American pastor Andrew Brunson, who had been held for two years in Turkey and was the focus of a diplomatic dispute between Ankara and Washington. Since Turkey’s decision to free him, the focus of tensions has shifted to the Saudis’ historic alliance with the United States.

Saudi Arabia has vehemently denied having anything to do with Khashoggi’s disappearance. Speaking a day after he was last seen, Mohammed, the crown prince, said in an interview with Bloomberg News that Turkish authorities were welcome to search inside the consulate building. “We have nothing to hide,” he said. 

But almost two weeks later, Turkish authorities are still waiting for access, and Saudi Arabia is not cooperating, two Turkish officials said Sunday. While the two countries have announced a joint investigative committee , the Saudi request for it is largely an attempt by Riyadh to convey the appearance of cooperation, said one Turkish official, speaking on the condition of anonymity to discuss the frustrations. 

“There is no joint investigation team,” he said, adding that Turkey is the only one actually investigating. “We accepted it because if we turned them down, they would have complained we were preventing them from cooperating.” 

While an earlier Saudi statement specified that the joint team’s purpose was to investigate, the one detailing Salman’s call on Sunday said its purpose was to “discuss” the disappearance. 

“There is no cooperation,” a senior Turkish official said. “They are not allowing Turkish investigators to bring in the equipment to do their work. We think what is happening now is Saudi Arabia is trying to buy time.”

A steady drip of leaks from Turkish officials has ratcheted up pressure on Saudi Arabia, but so far Turkey has not released all the evidence it has told U.S. officials it possesses. That may be attributable to efforts to reach an agreement with Riyadh in which it can save face and prevent completely blowing up the bilateral relationship, said Soner Cagaptay, a Turkey analyst at the Washington Institute for Near East Policy.

The two countries are probably working toward a “graceful exit” he said, “where they blame rogue elements of the Saudi state and throw one big significant name under the bus.” Turkey may also be reluctant to release audio if it obtained it by bugging the Saudi mission in violation of the Vienna Convention, he said.Turkish newspapers have reported that the recording may have come from Khashoggi’s Apple Watch, but that claim remains unverified  

The senior Turkish official also said he suspected that Saudi Arabia was preparing to “throw someone under the bus.”

As the crisis brewed, Saudi Arabia reminded its citizens that sharing “fake news” that might affect public order and security is punishable by a five-year prison sentence and an $800,000 fine, the Saudi Gazette reported, citing a Public Prosecution statement. 

In an interview with Lesley Stahl of CBS’s “60 Minutes” airing Sunday evening, Trump called the journalist’s suspected murder “really terrible and disgusting.”

“We would be very upset and angry if that were the case,” he said of Saudi Arabia’s potential responsibility. “As of this moment, they deny it, and they deny it vehemently. Could it be them? Yes.”