Warning of "severe disruptions" from the coronavirus outbreak, the US Federal Reserve today rolled out another series of measures to pump funds into the economy.

This includes buying unlimited amounts of government debt. 

The Fed has already announced it would buy at least $500 billion of Treasury debt as well as $200 billion of mortgage-backed debt, but now has committed to buying "in the amounts needed to support smooth market functioning," a move akin to printing money. 

In addition, the Fed said it would soon unveil a programme to lend directly to small and medium-sized companies.

SMEs have been hardest hit by the near complete shutdown of the US economy as authorities fight to contain the spread of the virus. 

"While great uncertainty remains, it has become clear that our economy will face severe disruptions," the Fed said in a statement, pledging to use all available tools to contain the damage. 

"Aggressive efforts must be taken across the public and private sectors to limit the losses to jobs and incomes and to promote a swift recovery once the disruptions abate," it added. 

In the latest action, the Fed revived facilities it last used during the 2008 global financial crisis, and expanded others announced in recent days. The three new programmes will provide an additional $300 billion in new financing. 

Economists praised the effort, but said massive stimulus from Congress is still needed.

"The downturn is not avoidable. The economic carnage associated with downturn can be mitigated so that there is an economy left to ramp up," said Diane Swonk, chief economist at Grant Thornton.

Ian Shepherdson, chief economist at Pantheon Macroeconomics, offered an equally dire warning: "The near-term threat to the economy is existential."

The central bank actions represent "an all-out effort to ensure that the business sector can continue to exist even as economic activity temporarily collapses. The Fed is now effectively the direct lender of last resort to the real economy, not just the financial system." 

The Fed pledged to "continue to use it full range of tools to support the flow of credit to households and businesses."

The programme amounted to unlimited quantitative easing since the benchmark interest rate already was cut to zero. 

One of the programmes, the Term Asset-Backed Securities Loan Facility (TALF), will help backstop recent student loans, car loans and credit card debt as well as small business loans. 

In addition, the Fed said it "expects to announce soon the establishment of a Main Street Business Lending Program to support lending to eligible small- and medium-sized businesses." 

US Treasury Secretary Steven Mnuchin said the government is "committed to providing relief for American workers and businesses, particularly small- and medium-sized businesses and critical industries that are most impacted by the coronavirus." 

"We will take all necessary steps to support them and protect the US economy," he said.