An economist who has advised President Trump said the potential effect of the coronavirus on the economy could be more detrimental than the disease itself if businesses aren’t allowed to resume operations within a matter of weeks.

“This can’t last for more than three weeks, or else the damage of shutting down businesses, shutting down workers, shutting down factories, people losing money on their 401(k)s, will be so significant that the cure may be worse than the disease,” Stephen Moore, a columnist for the Washington Examiner magazine, told radio show host John Catsimatidis on Sunday.

Several states, including Illinois, California, and New York, have ordered their residents to stay at home to try to stop the spread of the virus. Other cities and states have shut down nonessential businesses and schools.

“America has the greatest economic engine in the history of the world. But we cannot keep it shut down,” Moore added. “We saw a couple of million people signing up for unemployment insurance this week. Those numbers are going to compound in the weeks to come. We might see 20 million people signing up for unemployment insurance if people can’t go to work.”

As of Sunday morning, the United States had more than 26,000 confirmed cases of the coronavirus, according to a Johns Hopkins University tracker. At least 340 U.S. citizens have died from the virus, and 176 have recovered.