Donald Trump has called Saudi Arabia’s handling of journalist Jamal Khashoggi's killing the “worst cover-up ever” as the US vowed to revoke the visas of those believed to be responsible.
The US president called the circumstances surrounding the killing "a total fiasco”. He added: "There should have never been an execution or a cover-up, because it should have never happened."
And in an interview with the Wall Street Journal, Mr Trump said for the first time that Saudi crown prince Mohammed bin Salman could have been involved.
"The prince is running things over there (in Riyadh)", he said.
The president told reporters he had spoken with the crown prince on Monday who denied having anything to do with Mr Khashoggi's killing.
Earlier, he said the Mr Khashoggi matter was handled badly by Saudi officials.
"Bad deal, should have never been thought of. Somebody really messed up. And they had the worst cover-up ever," Mr Trump told reporters at the White House.
His comments came as Secretary of State Mike Pompeo announced that 21 suspects thought to be involved in the plot would have their US visas revoked or be made ineligible for US visas.
Mr Trump spoke hours after Turkey's president, Tayyip Erdogan, dismissed Saudi efforts to blame Mr Khashoggi's death on rogue operatives.
Mr Erdogan urged Riyadh to search "from top to bottom" to uncover those behind Mr Khashoggi's death in the Saudi consulate in Istanbul on October 2.
He said evidence suggests dissident journalist Jamal Khashoggi "was the victim of a very cruel murder".
He alleged his killing was intricately planned, with Saudi operatives taking the step of removing CCTV hard drives from the Saudi embassy in Istanbul before the killing took place.
Mr Khashoggi, a critic of the crown prince, was a US resident and Washington Post columnist. On Tuesday, his son was pictured grimly shaking hands with the crown prince in front of armed security guards as the royals received the murdered journalist's family members at the Yamama Palace in Riyadh.
Mr Trump's comments in recent days have ranged from threatening Saudi Arabia with "very severe" consequences and mentioning possible economic sanctions, to more conciliatory remarks highlighting the country's role as a US ally against Iran and Islamist militants, as well as a major purchaser of US arms.
Mr Pompeo said the State Department was looking into whether sanctions could be applicable for those found to be involved.
He said: "As we continue to develop our understanding of the individuals that were responsible for this, not only those who executed it but those who were connected to it, the world should know that we intend to hold those individuals accountable when we develop this fact set.”
"These penalties will not be the last word on this matter from the United States.”
The Saudi Embassy in Washington did not respond to a request for comment on the US measures.
Saudi Arabia has detained 18 people and dismissed five senior government officials as part of an investigation into Mr Khashoggi's death.
One of those fired includes Saud al-Qahtani, a top aide who ran social media for Prince Mohammed. According to two intelligence sources, Mr Qahtani ran Mr Khashoggi's killing by giving orders over Skype.
Turkish security sources say that when Khashoggi entered the consulate, he was seized by 15 Saudi intelligence operatives who had flown in on two jets just hours before.
