"The loss of thousands of small- and medium-sized businesses across the country would destroy the life's work and family legacy of many business and community leaders and limit the strength of the recovery when it comes," says U.S. Federal Reserve Chairman Jerome Powell.

WASHINGTON, May 13  -- U.S. Federal Reserve Chairman Jerome Powell on Wednesday said the COVID-19 crisis raises "long-term concerns," warning that a prolonged recession and weak recovery could lead to an extended period of low productivity growth and stagnant incomes.

"The scope and speed of this downturn are without modern precedent, significantly worse than any recession since World War II," Powell said in prepared remarks webcast by Washington-based think tank Peterson Institute for International Economics (PIIE).

The central bank chief said while the economic response has been "both timely and appropriately large," it may not be the final chapter, given that the path ahead is both "highly uncertain" and subject to "significant downside risks."

The Dow Jones Industrial Average plunged over 500 points following the Fed chairman's remarks, indicating investors' concerns over the prospect of economic recovery as U.S. states race to reopen.