Economic guru Jeremy Siegel warned the U.S. could suffer a near-term recession because of the negative economic impact from the fast-spreading coronavirus.

“We could really have a short, quick recession,” the Wharton School finance professortold CNBC. “There’s a lot of uncertainties.”

Still, Siegel believes long-term investors should stand firm as the swift market correction took valuation down to reasonable levels.

 “The long-term value is not significantly impaired,” Siegel said. “We were a little bit overextended at the end of January, so we are taking off that fluff. Now, I think we are down to the position where we have long-term value. In my opinion, stay the course for all the long-term investors,” he said.

“If you have a lot of cash, I would put some to work going forward,” he added.

A fall in GDP in two consecutive quarters typically defines a recession. The U.S. economy grew 2.1% in the fourth quarter last year and 2.3% for the full year 2019.

The U.S. economy is likely growing at a 2.7% annualized rate in the first quarter, based on the latest economic data, the Atlanta Federal Reserve’s GDPNow forecast model showed on Monday. That compared to a 2.6% pace estimated by the Atlanta Fed’s GDP program issued late last week.

Meanwhile, the New York Fed is less optimistic but raised its forecast Q1 by 0.1 percentage point. The New York Fed Staff Nowcast stands at 2.1% for the first quarter. "Positive surprises from manufacturing and housing data accounted for most of the increase," the New York Fed said.

Elsewhere, Heritage Foundation economist Stephen Moore is urging Americans to not be “freaked out and panicked” over stock market losses triggered by the coronavirus outbreak.

In an interview with radio host John Catsimatidis, Moore, a White House ally, said the economy will spring back once authorities determine a treatment for the fast-spreading virus, The Hill reported ahead of the Sunday interview airing.

“People should not be freaked out and panicked,” he said, adding: “People oftentimes make the mistake of … following the herd, and sometimes they follow the herd right over the cliff,” Moore said. “As soon as these viruses hit, the stock market falls by five or 10 or 12 percent, just as has happened now,” he said. “Once we have [a cure] … then the market goes right back up on its merry way.”

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