Riyadh, Saudi Arabia CNN  — 

Saudi Crown Prince Mohammed bin Salman on Wednesday described the killing of Washington Post columnist Jamal Khashoggi as a “heinous” crime in his first comments since some of his closest aides were implicated in the Saudi journalist’s death.

Speaking at an investors’ conference in Riyadh that has been overshadowed by the crisis, bin Salman said those responsible for the killing would be brought to justice.

“This was a very, very painful incident for all Saudis and also for everybody on this planet. It was unnecessary,” he said.

The crisis has presented a threat to bin Salman in a way that a bloody war in Yemen, the alleged abduction of the Lebanese Prime Minister and a crackdown on dissent at home have not. After Saudi Arabia admitted over the weekend that Khashoggi was killed October 2 in its Istanbul consulate, five high-ranking officials were dismissed, including bin Salman’s media chief and the deputy head of the Saudi intelligence service. Eighteen people were arrested.

Riyadh has maintained that neither bin Salman nor his father, King Salman, knew of the operation to target Khashoggi. US officials have said such a mission – including 15 men sent from Riyadh – could not have been carried out without the authorization of bin Salman, the country’s de facto ruler.

“Saudi Arabia will go and implement all necessary rules and investigate deeply in order to achieve results. And to bring to justice those who are responsible for this heinous crime, and they will be put before courts,” bin Salman told his audience in Riyadh on Wednesday.

In its public admission Saturday, Saudi Arabia claimed that Khashoggi died when a discussion turned violent. In private, officials have offered a shifting narrative. In the latest version offered by an official, the original plan was to persuade Khashoggi to return to Saudi Arabia, and if he refused, to drug him and take him to a safe house in Istanbul. But Khashoggi became agitated, the official asserted, and he died in a chokehold.

Saudi Crown Prince Mohammed bin Salman arrives Wednesday for the investors' conference in Riyadh.

On Wednesday, Saudi Energy Minister Khalid Al Falih admitted the scandal of Khashoggi’s killing was a blow to the kingdom.

“It’s not a death, it’s a murder. We admit it, we’re dealing with it. As such, we will be transparent and show our allies and friends in the United States … that the kingdom is as unhappy about what has happened as anybody else. In fact, we are more unhappy because it has tarnished the name of the kingdom,” he said while speaking to CNN on the sidelines of the conference.

However, he added that Saudi Arabia would emerge from the crisis stronger.

Turkey has rejected the notion that Khashoggi fell victim to a rogue operation. Turkish President Recep Tayyip Erdogan described the death Tuesday as a “ferocious” premeditated murder. Speaking Wednesday at the presidential palace in Ankara, Erdogan once again made clear he was not satisfied with the Saudi explanation.

“We are determined not to allow those responsible – those who ordered the crime and those who committed it – to escape justice,” he said.

Bin Salman insisted that good working relations between Saudi Arabia and Turkey should not suffer as a result of the crisis. “We will be sure to see that we cooperate with each other, that justice will be done,” he said.

Earlier Wednesday, bin Salman and Erdogan discussed the journalist’s killing in a phone call, according to Turkey’s state news agency Anadolu and the Saudi Press Agency. The Saudi crown prince requested the call to discuss a joint effort to shed light on all aspects of the death, Anadolu reported, citing Turkish presidential sources.

Saudis’ new version of events

In the latest iteration of a shifting story, Saudi officials told CNN that the original plan was to convince Khashoggi, who had been writing critical columns in The Washington Post, to return to Saudi Arabia. If Khashoggi refused, an official said, the next step was to drug him with a tranquilizer and take him to a safe house in Istanbul for 48 hours. If Khashoggi still refused to return to Saudi Arabia at that point, the team was to leave, and a “local collaborator” was to let him go, the source said.

The Saudi official also claimed that a forensic expert was present to erase all evidence of Khashoggi’s presence at the consulate and safe house, so that there would be no proof if the journalist later said he had been kidnapped.

The official provided no corroborating evidence for this new version of events. The New York Times has reported that the forensic expert was equipped with a bone saw.

The official said that of the 15 Saudis who took part in the operation, nine were at the consulate, with “three or four to question him and the rest to handle logistics.” There was no explanation why three to four people would be needed for questioning, or what logistics the others would attend to.

The rest of the 15-man team that Turkey said was a hit squad, including generals and their security detail, waited at the safe house, according to the source.

Saudi journalist Jamal Khashoggi with his Turkish fiancée, Hatice Cengiz.

Turkish officials have said that Khashoggi was set upon immediately after entering the consulate and then beaten, tortured and dismembered.

Turkish investigators last week searched the Saudi Consulate and consul general’s residence in Istanbul as they hunted for clues to Khashoggi’s fate. A well-placed Turkish official told CNN on Wednesday that permission to search the well at the consul’s residence was not given to Turkish investigators at that time.

President Donald Trump on Tuesday described the Saudi handling of Khashoggi’s death “the worst cover-up ever.” US Secretary of State Mike Pompeo said the United States would be revoking the visas of those who killed Khashoggi, and said that the administration has “identified at least some of the individuals responsible.”

UK Prime Minister Theresa May said Britain also was taking action against any Saudi suspects in Khashoggi’s death and that any individuals holding UK visas would have them revoked.

“We condemn the killing of journalist Jamal Khashoggi in the strongest possible terms,” she said. “And after his disappearance we made clear that Saudi Arabia must cooperate with Turkey and conduct a full and credible investigation.”

CNN’s John Defterios and Adrian Lydon reported from Riyadh and Elise Labott from Washington, while Laura Smith-Spark wrote from London. CNN’s Hamdi Alkhshali, Isil Sariyuce, Gul Tuysuz, Hande Atay Alam, Nimet Kirac and Mahatir Pasha contributed to this report.