Biden names pandemic recovery team

US President-elect Joe Biden named several women to his top economic policy team, including former Federal Reserve chair Janet Yellen as Treasury secretary nominee, setting the stage for a focus on recovery from the pandemic.

The advisers, several of whom would need to be approved by the US Senate, come from liberal research organisations and worked in previous Democratic administrations.

Their aim will be to set policies that can help people and businesses recover from the damage done by the coronavirus pandemic, which has killed nearly 267,000 people in the United States and cost millions of jobs.

"This team looks like America and brings seriousness of purpose, the highest degree of competency, and unwavering belief in the promise of America," Biden said in a statement on Monday.

Biden will formally introduce the new economic team members on Tuesday.

Arizona and Wisconsin on Monday certified Biden as the winner in each state, further undermining President Donald Trump's attempts to dispute his loss to Biden in the November 3 election by making unsubstantiated claims of fraud.

Most of the battleground states that Biden won, including Pennsylvania and Georgia, previously certified their results.

The Trump campaign is pursuing long-shot legal cases that seek to overturn Biden's victories in Georgia, Michigan and Nevada, while others have been dismissed or withdrawn in Pennsylvania, Michigan, Wisconsin and Arizona.

None has scored significant gains for Trump.

Yellen, 74, was head of the US central bank from 2014 to 2018 and had served as the chair of President Bill Clinton's Council of Economic Advisers.

Ron Wyden, the top Democrat on the Senate finance committee, said Yellen's confirmation hearing should occur before Biden's January 20 inauguration.

"When millions of workers are unemployed through no fault of their own and sectors of the economy are struggling mightily, there is no excuse for delay," Wyden said.

Senate Majority Leader Mitch McConnell, who like many top Republicans has not yet acknowledged Biden as president-elect, did not respond to questions about pre-inauguration hearings.

Control of the Senate - and the power to confirm or block Biden's cabinet appointees - will be determined by two run-off elections in Georgia on January 5.

The electoral college meets on December 14. Biden has 306 electors to Trump's 232.

Neera Tanden, chief executive of the Center for American Progress, is nominated to head the Office of Management and Budget.

Tanden helped the Obama administration create the Affordable Care Act, the healthcare overhaul popularly known as Obamacare, which Republicans have tried to dismantle.

Republicans voiced few concerns about Yellen, with Senator John Cornyn telling reporters he didn't "have any problem with her".

He was more concerned about Tanden, calling her the "worst nominee so far".

Biden selected Cecilia Rouse, an economist who is dean of the Princeton School of Public and International Affairs, to chair the Council of Economic Advisers.

She was a member of the council under Obama from 2009 to 2011.