President Donald Trump reacted to the economic fears surrounding the coronavirus on Monday, leading to a stock market drop of over 1,000 points.

“The Coronavirus is very much under control in the USA,” he wrote. “We are in contact with everyone and all relevant countries.”

The president praised the Centers for Disease Control and Prevention and the World Health Organization for “working hard and very smart.”

The Coronavirus is very much under control in the USA. We are in contact with everyone and all relevant countries. CDC & World Health have been working hard and very smart. Stock Market starting to look very good to me! — Donald J. Trump (@realDonaldTrump) February 24, 2020

President Trump expressed optimism about the stock market, despite big losses suffered on Monday.

“Stock Market starting to look very good to me!” he wrote.

The Dow Jones Industrial Average closed down 3.5 percent, falling 1,031 points. It was the biggest drop since February 2018.

Outbreaks of the virus in China have affected supply chains of products to the United States, as factory output has diminished amid the ongoing outbreak.

The disease is also spreading to other countries, including South Korea, Iran, and Italy.

There are now 53 confirmed cases of coronavirus in the United States, according to the CDC, after 39 U.S. nationals were brought back from a cruise ship that remains docked in Japan.