JUST IN: Biden Expected to Pick Janet Yellen as Treasury Secretary

Yellen, who would be the first woman to serve in the role, served as chair of the Federal Reserve from 2014 to 2018 under Presidents Barack Obama and Donald Trump.

"Yellen will be the next treasury secretary" and she could be formally announced as early as Tuesday, the source told AFP, confirming news first reported by The Wall Street Journal.

Although talks have intensified in recent weeks, Democrats, lead by House Speaker Nancy Pelosi (D-CA) and Senate Minority Leader Chuck Schumer (D-NY), are holding out for an expensive stimulus package that runs upwards of $2.2 trillion. She is widely seen as an moderate candidate, though recent public statements suggest she would be much more willing to expand spending than current secretary Steven Mnuchin, who recently drew criticism for ending several emergency lending programs. Elizabeth Warren (D-MA), signals that his administration will attempt to work with the congressional GOP upon taking office. After leaving the Fed, Yellen became a distinguished fellow in residence at the liberal Brookings Institution in Washington, signaling her continuing interest in financial policymaking. Some of them charged that Yellen and her predecessor, Ben Bernanke, had elevated the risk of runaway inflation and asset bubbles that could destabilize financial markets. On the contrary, under Bernanke and Yellen - and later, under Powell - the Fed's more hard challenge became raising inflation merely to the Fed's annual 2% target level. Last week Mr Biden said he had decided on his Treasury Secretary, though declined to say who it was.

Yellen has the support of many progressive groups, said Jeff Hauser, executive director of the Revolving Door Project, a left-leaning organization. She raised rates higher than they needed to be and stumbled along at the Fed.

As chairwoman of the US Federal Reserve, Ms Yellen was known for focusing more attention on the impact of its policies on workers and the costs of America's rising inequality.