IMF chief Kristalina Georgieva on Friday endorsed US President Joe Biden's proposed $1.9 trillion economic stimulus plan to deal with the pain caused by the Covid-19 pandemic.

"The US does have fiscal space to take additional relief and support measures," she told reporters.

And it is "appropriate" to use that firepower "given the exceptional uncertainties, and most importantly, given the fact that there is still a lot of pain for households and businesses."

Far from considering the package excessive, Georgieva expressed support for many of the proposal's elements including funding for vaccines, testing, food assistance, as well as tax credits for low-income workers.

"The fund has been a big proponent of using even more Earned Income Tax Credit (and) refundable childcare credit," she said during an event with reporters.

Biden on Friday pledged to "act fast" to push the legislation through Congress, even as Republicans have balked at the high price tag for the plan that enjoys broad popular support.

Democrats hold a narrow majority in the Senate, so they could approve the measure without Republican support.

Republicans also have opposed providing aid to struggling state and local governments, but Georgieva said conditions make that aid necessary.

"There is clearly a need to support states and local governments... so they can provide the services that are expected from them," she said.

A US recovery would have benefits for the global economy, and spending by Washington on areas such as education serves as an important "signal" to the rest of the world, she said.

Georgieva agreed on the need to "be watchful of risks" such as rising government debt, but "we have the best possible secretary of the Treasury for this potential risk to financial stability," she said, referring to Janet Yellen.