Turkish and Saudi authorities have now been told to launch a "credible investigation" into Mr Khashoggi's disappearance.
In a "60 Minutes" interview that aired on Sunday, Trump said there would be consequences if it turned out Saudi Arabia had anything to do with Khashoggi's mysterious disappearance.
The White House is brushing aside threats by Saudi Arabia that it may economically retaliate for any US punitive action imposed over the suspected murder of journalist Jamal Khashoggi, pledging a "swift, open, transparent investigation" into his disappearance.
The political fallout of the disappearance and possible death of Saudi writer Jamal Khashoggi has continued to reverberate around world, casting a cloud on a major investment conference aimed at promoting Saudi Crown Prince Mohammed bin Salman's plans for the kingdom.
The journalist was a one-time Saudi royal family insider turned critic who left the nation past year and began writing pieces for The Washington Post.
Turkish police investigators entered the Istanbul consulate late on Monday.
"The king firmly denied any knowledge of it", Trump told reporters after speaking with King Salman.
In Istanbul, Turkish authorities have been allowed into the consulate to conduct searches.
A security official holds barriers during the arrival of Saudi officials at Saudi Arabia's consulate in Istanbul, Turkey October 15, 2018.
"The denial was very, very strong", Trump later told reporters at the White House."It sounded to me like maybe these could have been rogue killers".
The press agency also released a statement of support from the government of Yemen, which Saudi Arabia is supporting in a protracted war against Iran-backed Houthi rebels in the Middle East's most impoverished country.
Yet Meyer says Saudi Arabia's threats are a "bluff" that amount to more of a tactic to save face in front of a domestic audience.
In a sign of new cooperation between Turkey and Saudi Arabia that could shed light on the disappearance, Turkish investigators wearing coveralls and gloves entered the consulate Monday.
Saudi Arabia had earlier denied killing Khashoggi and denounced such assertions as "lies", saying he left the building shortly after entering. I am immediately sending our Secretary of State to meet with King!'
Saudi Interior Minister, Prince Abdulazizbin Saud bin Naif bin Abdulaziz, "stressed that what has been circulating in terms of supposed orders to kill Jamal are outright lies and baseless allegations against the Kingdom's Government, which is committed to its principles, rules and traditions and is in compliance with worldwide laws and conventions". "Nobody's seen it yet, so we do want to see it. we're going to be seeing it very soon".
Business barons including British billionaire Richard Branson and Uber CEO Dara Khosrowshahi, as well as media powerhouses Bloomberg and CNN, have pulled out of the Future Investment Initiative (FII).
Steelers don't expect Bell to report this week
Bell told ESPN's Jeremy Fowler earlier this month that he meant to report to the Steelers during the Week 7-8 timeframe. Bell has deployed a strategy that has kept Steelers officials and players in the dark, with no contact with any of them.
Liverpool do not want to sign Aaron Ramsey
That means that, as things stand, the Wales worldwide would be able to leave on a free transfer in the summer. According to resources at ESPN FC , Manchester United and Chelsea are keen on signing the Welshman.
Astros Bring Split ALCS Home to Houston
Sale picked up the win in Game 1 of the AL Division Series against the Yankees when he pitched into the sixth inning. Sale was admitted Sunday afternoon to Massachusetts General Hospital, where he stayed for overnight observation.