On Wednesday, Powell said the economy's path forward will partially depend on policy actions taken at all levels of government to provide relief and support as needed.
Bank boss Jerome Powell said the Fed had noted the spike in new USA cases was denting economic activity and warned the downturn was "the most severe of our lifetimes", while adding that recovery depended on staunching the virus so Americans could go out and spend again.
The Federal Reserve left interest rates near zero and vowed to use all its tools to support the recovery from an economic downturn that Chair Jerome Powell called the most severe "in our lifetime".
Both types of swap line will now run until March 31 next year, the Fed announced at the end of the July 28 and 29 Federal Open Market Committee meeting. More than 150,000 Americans have died from COVID-19, the respiratory illness caused by the novel coronavirus.
"The Committee expects to maintain this target range until it is confident that the economy has weathered recent events and is on track to achieve its maximum employment and price stability goals", the statement said.
The dollar extended its decline on the Fed announcement, while USA stocks maintained their gains and gold remained buoyant.
The U.S. dollar fell to a two-year low and was on course for its worst month in a decade, making bullion cheaper for investors holding other currencies.
"I think many FOMC members were discouraged by the resurgence in COVID-19 across much of the Sun Belt this summer and the subsequent pullback in economic activity", said Mark Vitner, senior economist at Wells Fargo & Co.
"It's a bit ominous, to be frank".
Observers said focus now turns to the next policy meeting in September, which could see more measures unveiled.
Fed plans to increase its holdings of Treasury securities and agency residential and commercial mortgage-backed securities at least at the current pace to support the flow of credit to households and businesses, over coming months and sustain smooth market functioning.
"Since the Fed last met, the United States economy has been treading water and there has been a resurgence in the virus".
The US central bank has rolled out almost a dozen new lending and credit programs to fight the economic fallout from the epidemic.
Recent labor market indicators point to a slowing in job growth, particularly among smaller businesses. Republicans are split over whether to support $1 trillion in new spending, and Democrats want a figure closer to the $3 trillion Congress has already committed to fight the crisis.