Busy agenda for Joe Biden's first 100 days

Every candidate in the heat of a US presidential campaign talks up their goals for the first 100 days in office and Joe Biden, the Democrat who challenged President Donald Trump and beat him, has done so for months.

From battling the coronavirus to rejoining the Paris climate agreement and immigration reform, a Biden presidency, he says, would change course on multiple fronts.

"We're going to have an enormous task in repairing the damage he's done," Biden said recently of his rival.

Here is a look at how the first 100 days of the Biden presidency might look.

Biden says he would immediately put a national strategy in place to "get ahead" of the virus and end the pandemic crisis.

That means a nationwide mask mandate and a plan that allows for free and widespread Covid-19 testing, boosting of US medical equipment manufacturing and making any future vaccine "free to everyone, whether or not you're insured."

Having accused Trump of undermining his own health experts, Biden has pledged to keep respected White House coronavirus task force member Anthony Fauci on board.

He also said he wants to "take the muzzle off our experts" and cancel the process to withdraw the United States from the World Health Organization, which Trump initiated in July.

Read: Joe Biden could erase much of Donald Trump's legacy as the US President

Effectively reopening the economy is another immediate priority, says Biden.

The Democrat, relying on his experience wooing lawmakers from both political parties, will demand Congress agree on a huge coronavirus relief package to assist struggling families and ravaged small businesses.

In July Biden unveiled his "Build Back Better" strategy, a $700 billion blueprint to create millions of jobs. Financing would come through tax hikes on the wealthiest Americans and on major corporations.

Biden has also pledged to invest heavily in renewable energies.

Biden has long called for comprehensive action to combat climate change in the United States, battered by growing numbers of hurricanes and wildfires in recent years.

"The first thing I will do, I will rejoin the Paris accord," Biden promised during his debut debate against Trump, who exited the landmark global agreement in 2017. "Because with us out, look what's happening. It's all falling apart."

Biden says he would also convene a climate summit of the world's leading polluters to "persuade" them to make more ambitious pledges to reduce carbon emissions.

Biden has adopted an ambitious $2 trillion climate change plan including a "clean energy revolution" that aims to achieve net zero emissions economy-wide no later than 2050.

He also promised to quickly reverse several of Trump's rollbacks of regulations on environmental standards.

Read: US polls: Donald Trump rages at 'bad things' in counting rooms, claims he 'won this election by a lot'

Biden has promised to quickly appoint a bipartisan national commission that would have 180 days to study the judicial system -- which the Democrat said is "getting out of whack" -- and propose reforms.

He has said he is "not a fan" of expanding the US Supreme Court beyond its current nine members.

But other Democrats have expressed a clear preference for the move now that Trump's third nominee to the bench, Amy Coney Barrett, has been confirmed, cementing its six-three conservative majority.

Biden, who authored numerous tough-on-crime bills when he was a senator, is also calling for sweeping criminal justice reform.

His plans include creating a grant program that encourages states to reduce incarceration and crime, ensuring housing for formerly incarcerated individuals and strategies to reduce repeat offending.

Biden has promised a substantial set of immigration reforms should he win the White House.

He has announced he would immediately create a federal task force to reunite more than 500 children who were taken from their parents by the Trump administration at the US-Mexico border.

Biden has described the separations as a "criminal" result of Trump's zero-tolerance policy aimed at deterring migrants from crossing into the US.

He would also rescind the travel bans that prohibit foreign nationals from several majority Muslim countries from entering the United States.

One of his more controversial steps could be action on the millions of undocumented people living in the United States.

"Within 100 days, I'm going to send to the United States Congress a pathway to citizenship for over 11 million undocumented people," Biden said in his final debate with Trump, on October 22.

He also pledged to let minor children who entered the country with their parents illegally -- a group of about 700,000 young people known as Dreamers -- to legally stay and take steps toward US citizenship.