White House economic advisor Larry Kudlow said Friday the plunging US stock market is overreacting to the coronavirus outbreak and urged against "panic."

"Given what we know factually, it looks to me like the market has gone too far," Kudlow, director of the White House National Economic Council, told reporters.

"Our threat assessment is low and the economy is fundamentally sound," he said. "I do not think people should panic."

Kudlow spoke as stock markets worldwide saw mass sell-offs, fueled by fears that the outbreak will wreak economic damage far beyond China.

White House economics advisor Larry Kudlow appeals for calm
White House economics advisor Larry Kudlow appeals for calm AFP / Nicholas Kamm

There have been 61 confirmed cases in the United States and health experts warn this could rise. Investors, meanwhile, are already spooked by the disruption to China's all-important economy.

The Dow Jones Industrial Average was down nearly 1,000 points, or 3.8 percent, in trading Friday. The broad-based S&P was also down 3.5 percent and the tech-rich Nasdaq 2.8 percent.

Hong Kong and Shanghai markets ended their week with deep losses.

Coronavirus China