The UK, France and Germany have pressed Saudi Arabia to provide facts for its widely derided account of the death of the journalist Jamal Khashoggi, as Turkey vowed to reveal the “naked truth” about what happened in the Saudi consulate in Istanbul earlier this month.

In an attempt to ease growing western doubts about the credibility of the Saudi position, the foreign minister Adel Al-Jubeir told Fox News on Sunday that Crown Prince Mohammed bin Salman knew nothing of any plan to kill Khashoggi and that the whereabouts of his body remained a mystery to Riyadh.

“This was an operation that was a rogue operation. This was an operation where individuals ended up exceeding the authorities and responsibilities they had,” Jubeir told Fox. “They made the mistake when they killed Jamal Khashoggi in the consulate and they tried to cover up for it.”

Western governments have become increasingly dismissive of the often conflicting accounts of the journalist’s death provided so far. In a joint statement released on Sunday, the UK, France and Germany said: “There remains an urgent need for clarification of exactly what happened on 2 October – beyond the hypotheses that have been raised so far in the Saudi investigation, which need to be backed by facts to be considered credible.”

Timeline Jamal Khashoggi's death: a Saudi version of events Show Saudi Crown Prince Mohammed bin Salman tells Bloomberg he understands Khashoggi left the consulate after “a few minutes or one hour”. Turkish authorities are welcome to search the diplomatic mission because “we have nothing to hide”, he says. The Saudi consulate in Istanbul tweets that is following up on reports of Khashoggi’s disappearance “after he left the building”. Saudi ambassador Walid bin Abdul Karim El Khereiji denies any knowledge of Khashoggi’s whereabouts, Turkish media says. Riyadh sends investigators to cooperate with Turkey. Consul general Mohammed al-Otaibi tells Reuters all talk of kidnapping is baseless. Otaibi gives Reuters a tour of the consulate. Around midnight, Turkish officials say Khashoggi was killed there. A Saudi statement describes the Turkish allegations as baseless. US ambassador Prince Khaled bin Salman tells Axios the kingdom had nothing to do with the case. Prince Khalid describes allegations against the kingdom as “malicious leaks and grim rumours”. Turkey and Saudi Arabia form a joint working group. Saudi Arabia’s interior minister describes claims in the media that there were “orders to kill [Khashoggi]” as “lies and baseless allegations”. Later, Turkish officials leak details and say he was dismembered with a bone saw. Donald Trump tweets that he had spoken with King Salman, who “denies any knowledge of whatever may have happened”. Saudi-owned al Arabiya TV says 15 men identified by Turkish media on 10 October as part of a hit squad were misidentified “tourists”. Turkish investigators are allowed to search the consulate building. Trump speaks with Mohammed bin Salman, then tweets that the crown prince “totally denied” any knowledge of what happened and Riyadh was launching a thorough investigation. The US secretary of state, Mike Pompeo, says Saudi Arabia has made a “serious commitment” to hold anyone responsible accountable. Saudi Arabia’s public prosecutor says investigations show a fistfight led to Khashoggi’s death. Eighteen people have been arrested and two officials close to bin Salman fired. A Saudi official tells Reuters 15 officials travelled to Istanbul to meet Khashoggi, who had expressed interest in returning home. They threatened to kidnap him; Khashoggi resisted, and was accidentally choked to death during attempts to stop him shouting. An official dressed in Khashoggi’s clothes to make it appear as if he had left the consulate. The body was given to a “local collaborator” who disposed of it. The team then lied to Riyadh to cover up the fact Khashoggi had died.

The UK foreign secretary, Jeremy Hunt, spoke to Al-Jubeir on Sunday to convey the British view that “nothing can justify this killing” and assert that the explanation provided was not entirely credible.

A Foreign Office source said: “Ultimately the strength of our response will depend on the extent to which the truth has been found, and our confidence that it cannot happen ever again.”

In his strongest comments to date on the case, the US president, Donald Trump, accused Saudi Arabia of lying about Khashoggi’s death as pressure built on his administration to toughen its stance.

Perhaps more ominously for the Saudis,Recep Tayyip Erdoğan, promised to provide on Tuesday full disclosure of the Turkish investigation into Khashoggi’s killing.

Up to now, the Turkish president and other senior government figures have remained cautious in their public statements, stopping short of pinning the blame on Saudi Arabia and referring instead to the prosecutors’ investigation. Pro-government Turkish newspapers have released information detailing how a 15-member team was sent to Istanbul to confront Khashoggi at the consulate.

It is alleged that Turkey has audio of his murder that would dispel Saudi suggestions he was killed inadvertently by throttling after resisting a plan by 15 Saudi officers to compel him to return to Riyadh.

Donald Trump, right, shakes hands with Saudi Arabia’s Crown Prince Mohammed bin Salman in Washington earlier this year. Photograph: Mandel Ngan/AFP/Getty Images

Erdoğan told a rally in Istanbul: “We are looking for justice here and this will be revealed … not through some ordinary steps but in all its naked truth.”

After two weeks of contradictory statements, the Saudi government claimed late on Friday that Khashoggi was strangled after a fistfight broke out between him and officials on 2 October at the Saudi consulate in Istanbul. Five officials, including a senior intelligence officer, were said to have been fired and 18 others arrested.

In a later explanation offered on Sunday, the Saudis claimed the initial plan was to capture and persuade Khashoggi to return to Saudi Arabia, but to release him if he refused to comply.

The Saudis have given no details on the whereabouts of his body, and there are reports that the crown prince is both surprised and angry at the strength of the reaction in the west.

Jubeir insisted on Sunday that the killing was “a terrible mistake”. “This is a terrible tragedy. Our condolences go out to them. We feel their pain,” he said. “Unfortunately, a huge and grave mistake was made and I assure them that those responsible will be held accountable for this.”

The Saudi Press Agency reported late on Sunday that Saudi King Salman and Crown Prince Mohammed bin Salman had called and Khashoggi’s son, Salah, to express their condolences.

Western governments are waiting for the full report from Turkish authorities before deciding on what punishment, if any, to impose on Riyadh.

Prior to the joint statement, ministers from France, Germany, the UK and Canada all criticised the Saudi version of events, which have changed over time, starting with the assertion that Khashoggi had left the consulate unharmed.

The German chancellor, Angela Merkel, said her country would not export arms to Saudi Arabia while the uncertainty persists. “There is an urgent need to clarify what happened,” she said. “We are far from having this cleared up and those responsible held to account ... As far as arms exports are concerned, those can’t take place in the current circumstances.

The UK’s Brexit secretary, Dominic Raab, was asked in an interview on BBC television if he believed the Saudi explanation. “No, I don’t think it is credible,” he said. “We support the Turkish investigation into it and the British government will want to see people held to account for that death.”

The French finance minister, Bruno Le Maire, said: “I note that the Saudi authorities have changed tack, admitted the facts and accepted some responsibility, so we’re making progress.”

In an interview broadcast on Sunday, Canada’s prime minister Justin Trudeau said he could cancel a $15bn (£8.7bn) defence contract with Riyadh over the killing.

Opinion against Saudi Arabia was also hardening in the US, but differences remained over the form of sanctions that should be imposed. Other options include diplomatic expulsions and curbs on arms sales.

A senior Republican senator said he believed the Saudi crown prince was responsible for Khashoggi’s death, and that the US had intelligence suggesting “very high-level” involvement. Senator Bob Corker of Tennessee said Bin Salman had “crossed a line” by apparently overseeing the death of Khashoggi.

Corker spoke soon after Trump acknowledged for the first time that Saudi officials had made false statements about Khashoggi’s killing. “Obviously there’s been deception and there’s been lies,” the president told the Washington Post on Saturday. Trump, though, stopped short of blaming Bin Salman, saying he would “would love if he wasn’t responsible”.

The treasury secretary, Steve Mnuchin, said the Saudi explanation of the dissident’s death was a “good first step” but “obviously not enough”. Mnuchin is scheduled to visit Riyadh on Tuesday for talks with Saudi officials on Iran and on countering the financing of terrorism. Mnuchin has, however, withdrawn from the so-called “Davos in the desert” conference that is being shunned by many US executives and media companies following Khashoggi’s death.

The controversy has put the kingdom, for decades a key ally in western efforts to contain Iran, under unprecedented pressure. It has also evolved into a major crisis for the crown prince, a Trump administration favourite widely known as MBS, whose image as a modernising Arab reformer has been gravely undermined.