The Axios poll released early Wednesday found that 56 percent of respondents said Trump's response to Saudi Arabia has been "not tough enough", while 32 percent said his response has been "about right".
The Saudi government has said Khashoggi died in a fist fight, but Canada and other countries say Riyadh's explanation lacks credibility and are calling for a detailed investigation.
Riyadh called the killing a "huge and grave mistake", on Sunday, but has sought to shield the crown prince from the widening crisis, saying Mohammed bin Salman had not been aware. The Saudi foreign ministry tweeted out a photo of the two men meeting, and U.S. Treasury spokesman Tony Sayegh said in a separate tweet that Mnuchin raised the Kashoggi investigation in his discussions with the crown prince.
Mr Erdogan said he believed King Salman was not aware of the plot to kill Khashoggi.
In order to be successful, any legal effort requires some level of cooperation from Saudi officials, which is why USA businesses must use whatever influence they have.
Organisers of the glitzy flagship Future Investment Initiative listed Prince Mohammed bin Salman among the "top speakers" for the second day of the three-day conference, after he made a brief appearance on Tuesday.
The US leader criticised the kingdom for one of the "worst cover-ups in the history of cover-ups".More news: The candidates looking to succeed Merkel as CDU leader
More news: Victims of Pittsburgh shooting identified
More news: Lionel Messi suffers gruesome injury during Barcelona match
He gave a detailed account of the suspects' whereabouts prior to and during the day of what he called Khashoggi's "savage" murder.
Visa records are considered confidential and Pompeo did not say which or how many Saudi officials would have their visas revoked.
"We have maintained since the beginning that the Khashoggi murder was premeditated", a senior Turkish official told The Washington Post shortly after the Saudi announcement on Thursday.
Pence, who spoke in Washington at an event hosted by The Washington Post, said whatever USA response the president decides to make will keep in mind the importance of US relations with Saudi Arabia - an alliance that he noted has been in existence since shortly after World War II.
In the U.K., - the country that topped the list of the European Union countries in terms of exporting arms to Saudi Arabia - the opposition called on the government to suspend arms sales to the kingdom. Al-Qahtani coordinated the arrests of hundreds of members of the elite of Saudi Arabia and carried out the arrest of the Prime Minister of Lebanon.
An adviser to Turkey's leader said on Wednesday Saudi Arabia's crown prince had "blood on his hands" over Jamal Khashoggi's killing, the bluntest comments yet from someone linked to Tayyip Erdogan about Riyadh's de facto ruler in connection with the death. "He s running things and so if anybody were going to be, it would be him".
Speaking on Tuesday at the Oval Office, the USA leader said his Turkish counterpart had been "pretty rough" on Saudi Arabia when he addressed the writer's killing in parliament earlier in the day. Instead he chose to let the Turkish media pour out leaks that challenged Saudi Arabia's numerous shaky claims.