U.S. President-elect Joe Biden urged lawmakers on Tuesday to pass a new coronavirus aid package that has been stalled in Congress for months, and promised more action to reactivate the economy after he takes office. "Right now, the full Congress should come together and pass a robust package for relief to address these urgent needs" Biden delivered his message as he formally introduced key members of his economic team, including Janet Yellen. Yellen, who would be the first woman to ever hold the post of treasury secretary, said the pandemic had ravaged the economy. "It's an American tragedy and it's essential that we move with urgency. Inaction will produce a self-reinforcing downturn, causing yet more devastation." Seen for the first time wearing a boot since fracturing his ankle over the weekend while playing with his dog, Biden was asked if he backed a $908 billion dollar bipartisan COVID relief proposal unveiled Tuesday. REPORTER: "Do you support the $900 billion stiumus proposal, sir?" BIDEN: "I just heard about it, I'll take a look at it when I get back." But one of Biden's picks for his economic team, Neera Tanden, tapped to head the Office of Management and Budget, faces a challenge winning Senate confirmation after a Washington career in which she has crossed powerful figures on both the right and left. The Indian-American chief executive of the Center for American Progress think tank, and a longtime aide to former Secretary of State and 2016 Democratic presidential nominee Hillary Clinton, would be the first woman of color to lead the OMB. TANDEN: "I am here today because of social programs, because of budgetary choices, because of a government that saw my mother's dignity and gave her a chance." Republican Senator Tom Cotton called Tanden "a partisan hack" on Twitter for once referring to Republican Senator Susan Collins as "the worst." Tanden is "unfit to be confirmed by the U.S. Senate," he wrote. Two runoffs in Georgia on Jan. 5 will determine whether Republicans maintain control of the Senate. Well before Tanden was named, some Republicans were threatening to block Biden's Cabinet picks.