REUTERS/Jonathan Ernst

Paul Krugman, Christine Lagarde, and Larry Summers ripped into President Trump's coronavirus response on Thursday.

"This is stupid beyond even my wildest fantasies," the economist and columnist tweeted about Trump's decision to restrict European travel to the US. "THE VIRUS IS ALREADY HERE."

"I doubt very much that diseases have passports and are aware of borders," the European Central Bank's president told CNBC.

Summers, a former US Treasury secretary, blamed the president's "imprudent rhetoric" for Thursday's brutal market sell-off.

Trump probably set "a new world record for presidential market value destruction," he tweeted.

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Paul Krugman, Christine Lagarde, and Larry Summers ridiculed President Donald Trump's coronavirus response on Thursday.

"This is stupid beyond even my wildest fantasies," Krugman, a Nobel Memorial Prize-winning economist and New York Times columnist, tweeted after Trump announced restrictions on travel from Europe to the US.

"THE VIRUS IS ALREADY HERE," he added.

Coronavirus — which causes a flu-like disease called COVID-19 — has infected more than 127,000 people including more than 1,300 in the US. It has killed at least 4,700 people and spread to upwards of 100 countries. Outbreaks in several US states have already led to school closures, major events being canceled, and the suspension of the NBA season.

Lagarde, the European Central Bank's president, also took issue with Trump's travel policy.

"I doubt very much that diseases have passports and are aware of borders," Lagarde said in a CNBC interview.

Trump revealed the travel restrictions in a televised address on Wednesday night, during which he failed to clarify who would be exempted and incorrectly said the rules applied to trade and cargo. He also said health insurers would waive copays for coronavirus treatments, when he seemingly meant to say tests.

The muddled speech, and a dearth of details about what the US government will do to soften the economic impact of coronavirus, spooked markets on Thursday. US and European stocks tumbled more than 8%, oil prices dropped, Treasury yields slid, and bitcoin lost more than 20% of its value.

Summers, a former US Treasury secretary and World Bank chief economist, tweeted at the president that he may well have set "a new world record for presidential market value destruction."

"He destroys about $500 billion in equity market value in the course of an 11-minute speech," he continued. "Destruction roughly doubles as investors take an hour to analyze the speech."

"Loose lips sink ships. Imprudent rhetoric sinks markets," he added.

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