Stocks have dropped as much as 9 percent since Khashoggi disappeared on 2 October after walking into the Saudi consulate in Istanbul.
But both the White House and the kingdom are under mounting pressure as concern grows over the fate of the veteran journalist, who hasn't been seen since he entered the Saudi Consulate in Istanbul on October 2.
Sen. Bob Corker, R-Tenn., who as chairman of the Senate Foreign Relations Committee has reviewed the US intelligence into what happened to Khashoggi, has said, "The likelihood is he was killed on the day he walked into the consulate".
While expressing support for joint Saudi-Turkish efforts to look into his disappearance, they said the Saudi government must provide "a complete and detailed response", indicating that such a message had been conveyed "directly" to Riyadh.
Sanders has criticized U.S. support for the Saudi-led coalition's military effort in Yemen and pushed for a vote earlier this year along with Utah Republican Sen.
In a blistering riposte to Mr Trump, a statement released by the state-controlled Saudi Press Agency said: "The kingdom affirms its total rejection of any threats or attempts to undermine it, whether through threats to impose economic sanctions or the use of political pressure".
Now in its fourth year, the war in Yemen costs Saudi Arabia billions of dollars a month and has shown the world that its military-even with the most advanced weaponry and US assistance-is incapable of even defending the country's own borders from lightly armed Houthi rebels and allied militias.
U.S. President Donald Trump is expected to call King Salman soon as questions mount about the disappearance of the Saudi journalist.
Saudi Arabia rejected threats of punishment, saying the kingdom would retaliate against any sanctions with "greater action", according to its official state news agency.
'If, as they say, this bad murder didn't happen then where is Jamal Khashoggi?
Khashoggi, a prominent critic of Saudi Crown Prince Mohammad bin Salman and a USA resident, disappeared on October 2 after visiting the Saudi consulate in Istanbul.
Saudi Interior Minister, Prince Abdulaziz bin 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".
The Turkish Daily Sabah newspaper reported on Saturday that a government investigation into the journalist's disappearance revealed that recordings made on his Apple Watch indicate that he was tortured and killed.
USA senators called for reactions ranging from boycotting an upcoming economic summit in Riyadh to ending support for Saudi military operations in Yemen. "We do want to see it".
"Whilst it is disappointing that some speakers and partners have pulled out, we are looking forward to welcoming thousands of speakers, moderators and guests from all over the world to Riyadh", a Future Investment Initiative representative said last week.
Kudlow calls the U.S.
"I do think that arms sales will be affected".
"There's been a hold for a long time", Senate Foreign Relations Chairman Bob Corker, of Tennessee, told CNN.
"If more information comes out over the next week, I will obviously take that into account".