SAUDI ARABIA warned it would retaliate against any sanctions imposed on the oil-rich kingdom over the disappearance of journalist Jamal Khashoggi, as the Riyadh stock market plunged on growing investor jitters.

From tech tycoons to media giants, a host of Western companies are now distancing themselves from the Gulf state, imperilling Crown Prince Mohammed bin Salman’s much-hyped economic reform drive.

U.S. President Donald Trump has threatened the kingdom with “severe punishment” if Khashoggi, who has been critical of Prince Mohammed, was killed inside its Istanbul mission.

But Riyadh vowed Sunday to hit back against any punitive measures.

“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,” an official said, according to state news agency SPA.

The official said Riyadh would “respond to any action with a bigger one,” pointing out that the oil superpower “plays an effective and vital role in the world economy.”

According to Saudi-owned Al Arabiya television, the kingdom has “over 30 measures” it could implement.

Following Riyadh’s assertion it would retaliate, Britain, France and Germany released a joint statement saying they were treating Khashoggi’s disappearance “with the utmost seriousness.”

“There needs to be a credible investigation to establish the truth about what happened, and — if relevant — to identify those bearing responsibility for the disappearance of Jamal Khashoggi, and ensure that they are held to account.”

This message had been conveyed “directly to the Saudi authorities,” said the statement, signed by Britain’s foreign minister Jeremy Hunt, his French counterpart Jean-Yves Le Drian and Germany’s Heiko Maas.

Khashoggi, a Washington Post contributor, vanished after entering the consulate Oct. 2.

Saudi Arabia insists Khashoggi left the building safely and dismissed accusations that authorities had ordered his murder by a hit squad as “lies and baseless allegations.”

Turkish officials have said they believe Khashoggi was killed inside the mission and claims have been leaked to media that he was tortured and even dismembered.

Saudi King Salman spoke to Turkish President Recep Tayyip Erdogan by phone Sunday, the Saudi foreign ministry said, telling Erdogan: “No one will get to undermine the strength of this relationship.”

According to a Turkish presidential source, who asked not to be named, Erdogan and the king discussed “the issue of shedding light on the case of Jamal Khashoggi” and also emphasized the “importance of creating a joint working group within the framework of the investigation.”

In the U.S., White House economic adviser Larry Kudlow said Saudi Arabia should take Trump’s warning over the journalist’s fate seriously.

“When the president warns, people should take him at his word,” he told Fox.

Investors have taken fright, prompting Saudi stocks to tumble by around seven percent at one point Sunday, wiping out their gains for 2018.

Business barons including British billionaire Richard Branson and Uber CEO Dara Khosrowshahi, as well as media powerhouses like Bloomberg and CNN, have pulled out of next week’s Future Investment Initiative (FII) in Riyadh.

JP Morgan CEO James Dimon and Ford chairman Bill Ford said Sunday they would also not attend. (SD-Agencies)