Coming into this debate, polling indicates that voters give Trump better marks on the economy and immigration – two of the top issues for Americans, according to opinion surveys.

Biden is favoured on the issues of abortion, healthcare and the environment.

The winner of Thursday night’s debate could well be the candidate who lands the best lines on their areas of strength, while defending their weaknesses.

Can President Biden convince voters he shares concerns about a surge in immigration, but his efforts were stymied by Republicans?

Will the former president find a way to convince voters another term in office won’t lead to greater restrictions on abortion – particularly given that he appointed three Supreme Court justices who voted to overturn Roe v Wade protections?

Biden has been trying for more than a year to convince the American public that the economy is better than they think it is.

He’ll have a chance to make the case again to an audience of tens of millions, but he’ll have to do so in the face of what’s sure to be withering attacks from his opponent, who is expected to focus on the inflation-driven higher consumer prices the country has seen since the start of the Biden presidency.

In the hours before tonight's CNN Presidential Debate, both candidates - and their political allies - have sent out a flurry of fundraising emails to gather donations from supporters.

In one email on Thursday afternoon, Donald Trump vowed to "try and read your responses before I step on the stage".

"Biden is a walking lying machine, so we need to be prepared for the worst," he said. "But with your advice in my ear, I’ll make him EAT THOSE WORDS when we meet on stage."

A Biden-Harris campaign email sent around the same time - ostensibly from Vice President Kamala Harris - urged supporters to "tune in and, if you're able to, make a contribution to the campaign".

"To win this election, defend democracy, and make more progress for the American people, we need a groundswell of support," Harris wrote. "Especially today".

An earlier email from the Biden-Harris campaign also accused Trump of inflicting "chaos" on the US and leaving the White House "unhinged" when he lost the 2020 election.

Both Biden and Trump have been in Atlanta for several hours now ahead of their highly anticipated debate.

Here's a look at what they've been doing before the big event.

Image source, Reuters

Image source, Reuters

Image source, Reuters

Image source, Reuters

Its nickname locally is The ThrillerDome. The McCamish Basketball Arena is home to Georgia Tech’s Yellow Jackets. Tonight, it’s the CNN Spinroom, home to politicians, analysts and journalists.

Both Joe Biden and Donald Trump are now in Atlanta, so activity has increased here as supporters arrive to support their guy to the dozens of US and international media gathered.

We’ve already heard from one of Donald Trump’s potential vice presidential picks - Congressman Byron Donalds from Florida - about why Donald Trump is the best option for America.

While California Governor Gavin Newsom is also in the spin room selling Joe Biden’s credentials.

Our special live coverage will start at 20:00 EDT (01:00 BST) and we have a panel of politicians, campaign supporters and administration insiders to talk us through what to expect before the debate begins.

After the debate, we’ll have lots of analysis and discussion. So do join us on this historic night in US politics.

You can watch the CNN Presidential Debate live by pressing the watch live button at the top of this page or on CNN.

Image source, Getty Images

You’re not having deja vu - voters have seen Donald Trump and Joe Biden debate each other before.

The two men went head-to-head twice during the last presidential race, in 2020.That was at the height of the pandemic.

Debate officials introduced several anti-Covid measures, including social distancing on stage and forgoing the traditional candidate handshake.

In fact, Trump was admitted to hospital with Covid-19 only a few days before the first debate in September.

Several White House aides have since said Trump had tested positive several days before the debate, though the former president denies this.

That debate was the third-most watched in US history, with more than 73 million viewers.

Viewers saw several dramatic moments as the two candidates clashed. Biden at one point called Trump a “clown” and a “liar”, and told the then-president to “shut up, man”.

Trump garnered criticism for addressing the far-right extremist Proud Boys group, telling them to “stand back and stand by” when asked to condemn their white supremacist positions. Commentators also noted Trump frequently interrupted Biden.

A second debate scheduled for early October was cancelled as Trump continued his Covid recovery.

They met again later that month for a more subdued second round, which had nearly 10 million fewer viewers.

Image source, Reuters

The White House Correspondent's Association, or WHCA, has said it is "deeply concerned" that traveling pool reporters have not been granted access to the CNN Presidential Debate in Atlanta.

In a statement, the WHCA - which is comprised of journalists who cover the president - said CNN "rejected our repeated requests" to include the travel pool, and it "urged" the network to grant at last one print pool reporter access for the duration of the debate.

CNN ultimately granted one print pooler permission to enter the studio during a commercial break to observe the setting.

"That is not sufficient in our view and diminishes a core principle of presidential coverage," WHCA president Kelly O' Donnell said in the statement.

In its own statement, CNN - which is a member of the WHCA - said that the event is "closed to press" and that has been made available to pool members and CNN affiliates, in addition to being available for embed via CNN's YouTube channel.

"Following our traditional approach, CNN is providing access to the debate studio for a tight pool of photographers for the duration of the event and a larger group of photographers during a commercial break," the CNN statement said, adding that a print pool reporter would also be allowed inside during the first commercial break.

Vice president Kamala Harris will watch the debate from Los Angeles, according to a Biden-Harris campaign official.

After the debate, she will deliver remarks on a virtual campaign watch party and organising call, the official said.

The vice president, who has a home in Los Angeles, appeared at a campaign fundraiser on Wednesday in Bradbury, California.

At the event, she said the debate "is going to frame [the] race," adding that Americans would see a stark contrast between President Biden and the former president.

"We're also going to see on that debate stage a Donald Trump who we know has always been unburdened by truth," she said.

Of course Trump has yet to reveal his pick for his vice presidential nominee, but several contenders - Senators JD Vance, Marco Rubio, Tim Scott and North Dakota Governor Doug Burgum - are in Atlanta to cheer on their potential running mate.

Image source, Reuters

America has a two-party political system. The Democrats (represented by Joe Biden) and the Republicans (represented by Donald Trump) dominate the field.

But there are a few other presidential candidates who have thrown their hats into the ring this year.

The most recognisable name is Robert F Kennedy Jr, a member of the country’s most famous political family.

RFK Jr has consistently polled in the teens or high single digits, percentage-wise. By all indications, he is the most popular independent or third-party candidate in decades.

But CNN has certain thresholds to qualify for this presidential debate, and RFK Jr didn’t reach them.

To get his own podium on the debate stage, candidates needed to hit 15% in at least four approved national polls and needed to appear on enough state ballots to be able to reach 270 electoral votes (that’s the magic number it takes to win a US presidential election). RFK Jr missed those cut-offs.

Kennedy is instead holding his own online event during the debate time, which his campaign is calling the “Real Debate.”

Campaigners in North Las Vegas are pouring bags of ice into drinks boxes and hitting doorsteps in boiling temperatures to speak to potential voters, before cooling off at a debate watch party this evening.

They are focussed on reaching Latino voters, who will be extremely important in a swing state like Nevada in deciding the eventual presidential winner.

The sense campaigns are seeing is that people are not as engaged at this stage in the race as they might have been in previous years, because both candidates are already well known to the electorate.

A group called Make the Road Nevada is trying to get Latino voters engaged with the issues that matter for their community.

Jose Rivera from the group said he has welcomed the rules put in place by the debate's host, CNN, which will prevent some of the more theatrical aspects of previous debates, such as noise from the audience and candidates talking over each other.

“I’m glad that the rules of the debate are the way they are,” he told the BBC.

“Cutting the mics when your time is up and having no audience because that allows the audience to be able to focus on the main issues that America is dealing with right now.

“We have a lot of folks working two or three jobs to be able to afford rent, to be able to pay their bills, so we’re going to be able to see these two presidential candidates focus on the main issues.

“What is it that they’re offering to our communities? What is it that they’re going to be promising?”

The campaigns are starting to tell us which high profile surrogates will make an appearance tonight.

One name jumped out from the Biden campaign's list: Mary Trump, the niece of the former president who has turned into one of his biggest public critics, will apparently attend. She has written two books about Trump and their family.

Other Biden campaign surrogates will include former Atlanta mayor Keisha Lance Bottoms, Georgia Senator Raphael Warnock, and members of Congress Jasmine Crockett and Robert Garcia.

The VIPs are already trickling in with several hours before showtime.

Spotted so far in the arena: Florida congressman Byron Donalds, a rumoured Trump vice presidential pick; California Governor Gavin Newsom, a Democrat and top Biden surrogate; and Georgia Governor Brian Kemp, a Republican who has found himself at odds with Trump in the past.

Biden and Trump will be facing off inside CNN headquarters in Atlanta tonight.

Here's a peek at what the debate stage looks like.

Image source, Reuters

Image source, Reuters

After arriving in Atlanta, Biden met with a group of supporters gathered outside the debate site. He hugged California Congressman Robert Garcia, a campaign surrogate who is here in support of the president, and shook hands with supporters carrying Biden signs.

"I met some incredible supporters who are fired up ahead of tonight’s debate," he tweeted. "Let's finish the job."

He is hunkered down at a nearby hotel until the debate, according to the White House.

Trump arrived in Georgia and is heading directly to the debate site, a campaign source told BBC's US media partner, CBS.

Image source, Getty Images

US elections are often watched closely around the world, and this one is no exception.

That is due to the weight America carries when it comes to foreign policy, and the impact the actions of the White House can have on cities and countries miles away from Washington, DC.

Our BBC News correspondents from around the world told us how this election re-match is making waves where they are.

Take Russia, for example, whose relations with the US have grown bitter since the invasion of Ukraine.

Whoever wins the race for the White House, the Russian authorities will be watching closely for signs of post-election political instability and polarisation in America, and looking for ways to benefit.

For Ukraine, however, the stakes could not be higher. Joe Biden has been a strong supporter of sending aid to Kyiv, while Donald Trump has talked about cutting aid and ending the war altogether.

With Israel-Gaza war ongoing, Jewish Israelis seem to prefer Trump over Biden, as most disapprove of Biden's handling of the war. Palestinians also widely see him as neglecting their suffering, but a Trump win could leave them worse off as he has promised to cut off all US aid to them.

When it comes to China, both candidates have vowed to be tough on Beijing. But the calculus may differ based on who wins.

An unpredictable Trump could weaken and divide US allies in the region - but he could also create another trade war. Beijing is not too keen on Joe Biden either, fearing his alliance building in the region has the potential to create a new Cold War.

You can read more from our correspondents on how the US election is being received globally here.

We're just under three hours away from the start of tonight's debate. It's stormy outside here in Atlanta, but inside the university basketball arena that has been converted into a media centre it's quiet and calm.

Joe Biden and Donald Trump will not actually be in this building - they'll go to head to head down the street in a studio without an audience. Two CNN anchors - Jake Tapper and Dana Bash - will be the moderators.

But it's here, where I am, where the battle to spin the debate in either candidate's favour will happen. After the 90-minute debate, surrogates and campaign staff from both sides will be doing their best to convince journalists, and the American public, that their man came out on top.

A few politicians and campaign aides have already wandering the red-carpeted spin room floor, stopping at camera positions to offer their views and predictions on what is to come.

The expectation-setting games are almost over, however,

We don’t know who will win tonight’s debate, but we do have a sense of what success looks like for each candidate.

Ironically, the aim is similar for both men: each wants to hold a mirror up to the other one.

For Biden, a win is making Trump look crazy. He wants to show Donald Trump at his most extreme and to goad him into being angry, rude, and erratic. Biden wants to remind American voters - who may have forgotten - how unorthodox the Trump presidency was.

For Trump, a win is making Biden look distracted or confused or just "old-seeming." He also wants to remind Americans that prices are higher than when he was president and that America’s southern border has been more porous under Joe Biden.

Image source, Getty Images

Both candidates are now on the ground in Georgia, the southern US state where tonight's debate is being held.

Donald Trump has just touched down, while Joe Biden landed not long ago.

Stick with us, we'll bring you all the latest news and analysis of the debate and beyond.

It was a long road to get to tonight’s debate.

For months, the Biden campaign would not commit to a debate with Trump, who also declined to appear in any of the Republican primary debates.

In March of this year, Biden said his decision to participate in the debate would depend on Trump’s “behaviour”.

Biden’s campaign had reportedly expressed concerns that Trump would not abide by the rules set for the debate. But this spring, the president announced he would participate in a debate against his Republican rival.

The two faced off twice in 2020 before the presidential election that Biden won that November.

This is the earliest presidential debate in modern US history – held before either candidate is the formal nominee of their party.

That means the showdown could set the mood and the measure of the campaign to come, solidifying some loosely held views about the candidates and better defining the issues and the stakes of November’s balloting.

Barring truly catastrophic mistake by one of the candidates, the early debate timing could means that when election day arrives, this June event will be a distant memory for the majority of Americans who only sporadically follow politics.

Both candidates will have a chance to reset and rebuild from any debate damage during their tightly scripted national conventions. And there’s another debate scheduled in September that could further erase what happens this week from voters’ memories.

It’s a reality that a senior Biden campaign aid, speaking to BBC media partner CBS, acknowledged.

“The June debate is not a moment that we expect to define the trajectory of the election or move poll numbers in the near-term," the advisor said, adding that voters will require “consistent time and effort” to win in November.

Where to catch-up post-debate

Anthony will pick over the bones of the debate in a special edition of his weekly newsletter US Election Unspun, on Friday.

Don’t miss his expert analysis.

Sign up here, if you’re in the UK. Readers in the rest of the world can subscribe here.

The tone among Georgia’s Democrats feels flat when they talk about this year’s presidential election.

Tried-and-true Democrats say they’ll vote for Joe Biden, but the affirmation often comes with a hint of reluctance.

"Joe Biden has my vote," Montye Benjamin says.

Mostly because of "who he's running against".

"Anything is better than Trump," says Benjamin.

The 60-year-old is still mourning the death of her son, Jayvis, who was shot and killed by Georgia police in 2013 at age 20.

She wishes Biden would have done more on police reform.

Siegfried White says he was thinking of not voting at all this year, but decided he will cast a ballot for President Biden.

"These 64 years of my life, every time I vote for a president they let me down," White says.

"I'm getting tired of getting let down."

For the most part, Republicans in the southern US state of Georgia - where tonight's debate is taking place - who voted for Donald Trump in 2020 remain steadfast in their conviction to send him back to the White House.

Some though, like Alyona Clement, are turning away from their party's standard-bearer.

Clement voted for Trump in 2016, but has since given up on him due to his numerous legal troubles.

"All the lawsuits that Trump is going through, all these women accusing him of stuff, that's what turned me off from him," Clement says.

Still, most Republicans who spoke to the BBC feel like Fran Diemer.

"I voted for Trump in 2016, and 2020, and I will vote for him again," Diemer says.

"He’s the best thing to ever happen to this country and we need him back."

Gloria Murphy, 73, echoed the sentiment.

"I think Trump did a great job in 2016," Murphy says, adding that she's more excited to vote for Trump than ever.

"The last four years have been terrible. Just look at the economy," she adds.