Bernd Debusmann Jr
Reporting from the debate in Philadelphia

Image source, Getty Images

I've been pacing up and down the venue's "spin room", looking for campaign officials and surrogates to speak to.

Just a few minutes ago, I ran into Byron Donalds, a Florida Representative who is among Donald Trump's closest allies on Capitol Hill.

"I'm feeling good," he told me, walking quickly to the next in a series of TV appearances he has scheduled for this afternoon. "Really good."

I asked him how he thought tonight will go for Trump.

"Donald Trump ended one political career two months ago," he added. "I think we'll see the beginning of the end of another one tonight," he said.

Steven Rosenberg
Moscow correspondent

Image source, Reuters

If you’re running for president, endorsements are always welcome.

Correction - almost always.

Last week Vladimir Putin said Russia would follow Joe Biden’s lead in "backing" Kamala Harris for US president, since Vice-President Harris "laughs so expressively and infectiously".

But the White House wasn't laughing.

US national security spokesman John Kirby has said President Putin “shouldn’t be favouring anybody, one way or another”. He added that the US would “greatly appreciate it” if the Kremlin leader would “A. stop talking about our election, and B. stop interfering in it”.

Russian state TV has since clarified (for those who hadn’t guessed) that President Putin was being "slightly ironic".

The Kremlin will know that, with US-Russian ties so strained, any public endorsement by Moscow is likely to do that candidate more harm than good.

Does that mean it’s Donald Trump who really has the Kremlin's backing ahead of the debate in Philadelphia?

Certainly, much of what Team Trump has said will have struck a chord with Moscow, including vice-presidential nominee JD Vance's criticism of US military aid to Kyiv and Donald Trump encouraging Russia to do “whatever the hell they want” to Nato member countries that don't meet defence spending guidelines.

Some commentators believe the Kremlin is hoping for a specific outcome in this election: a tight race, resulting in a disputed result, political paralysis, and chaos.

In a recent social media post Russia’s hawkish former president Dmitry Medvedev wrote of an “inevitable new civil war” in America that would lead to the “disintegration” of the US.

Laura Bicker
China correspondent

Kamala Harris is an unknown quantity to leaders in Beijing. She has no track record on China and she has mentioned it publicly only once – stating that the United States, not China, would win the competition for the 21st Century.

She represents something China does not like – uncertainty. So, leaders will be watching this debate for clues on what her US-China policies may be.

President Xi Jinping used a recent visit by the US National Security Adviser Jake Sullivan to call for “stability” between the two superpowers – perhaps more a message to the current vice-president than Joe Biden as the outgoing commander-in-chief.

The prevailing view among Chinese academics is that Harris will not stray too far from President Biden’s slow and steady diplomatic approach.

In contrast, the Chinese know a lot about Donald Trump. He represents something else they don’t particularly like – unpredictability. They fear he wants to pick a fight with Beijing, and he has already threatened to impose 60% tariffs on Chinese imports which raises the spectre of another costly trade war. China is trying to export its way out of an economic downturn, so this will be a huge concern.

Whether it’s Harris or Trump - there’s little hope in Beijing that US policy on China will change significantly with either candidate. The belief is that Washington is trying to contain China’s rise – no matter who sits in the White House.

Courtney Subramanian
Reporting from Washington DC

President Joe Biden told reporters before leaving the White House for a trip to New York that he spoke to Kamala Harris ahead of tonight's debate.

In June, it was Biden's own calamitous debate performance against Trump that led to his eventual exit from the race.

"She seems calm, cool and collected. I think she's going to do great," he said of his call. "And I'm not going to tell you what advice I gave her."

Lyse Doucet
Chief international correspondent

The topic of Afghanistan has rarely surfaced as of late in US politics. But it’s likely to be on Donald Trump’s charge sheet when he faces off against Kamala Harris.

The most recent of many reviews, by House Republicans, points an accusing finger at President Joe Biden’s team for the Taliban’s return and the chaotic US pull-out from the country.

But when it comes to blame for the US debacle, there’s plenty to share.

Mistakes and misunderstandings span four administrations, both Republican and Democratic. Systemic failures goes back to decisions made in the months after the fall of the Taliban in November 2001, during President George Bush’s time in office, all the way to the months leading up to the fall of the US-backed government August 2021, under Biden's watch.

In 2020 we saw, month after month, the repercussions of Trump’s pledge to bring all US troops home. The Taliban knew victory was in sight.

In 2021 we saw Biden vow to end America’s longest war, which informed every fateful decision from that point.

Afghan missteps were also in this mix.

The speed of the Afghan government’s collapse in 2021 took everyone, including the Taliban, by surprise. But it was set in motion a very long time before.

Both presidential contenders can pick the moment which mattered most leading up to that moment.

Nick Beake
BBC's Europe correspondent in Kyiv

Image source, EPA

More than anything else, what Ukrainian President Volodymr Zelensky would want to hear from the two US presidential candidates is a commitment that if elected they’d grant him permission to use American-made ATACMS long-range missiles to strike Russian airfields.

But that’s hugely unlikely, with no indication Kamala Harris would undermine President Biden’s current public position and Donald Trump boasting he could end the war in 24 hours.

Plus, President Zelensky says Ukraine needs this permission now - not at the start of next year, which is when the new US leader takes office.

So in the absence of the one thing Kyiv argues would weaken Russian President Vladimir Putin and ultimately bring him to the negotiating table, it wants to hear that American support is not going to fade away.

Kamala Harris says she will "stand strong with Ukraine" and represents continuity with the Biden approach.

In contrast, Donald Trump appeared to criticise the recent Ukrainian incursion into Russia, saying we’re going to end up in "World War Three".

As for his running mate? In the days after the full-scale invasion in 2022, JD Vance said "I don't really care what happens to Ukraine one way or another."

The first presidential debate back in June showed how important these events can sometimes be, with Democrats essentially forcing Joe Biden to drop out after his shaky performance.

Before that debate the race had been relatively close, with Biden trailing Trump by less than one percentage point in the national polling average - but afterwards, the Republican appeared to open a greater lead.

When Kamala Harris hit the campaign trail at the end of July, Trump’s advantage evaporated and it was the Democrat who found herself with a small lead that she has maintained since.

But things can change quickly, especially when there’s only a couple of percentage points between the two candidates - which is why we’ll be keeping a close eye on the polls in the days after tonight’s debate.

Follow more about the latest news about US electionpolls.

Nada Tawfik
Reporting from Philadelphia

Image source, Nada Tawfik / BBC

Where there’s a US political event, you’re sure to find merch nearby!

LaJohn Robinson has been following Vice-President Kamala Harris on the campaign trail to sell his shirts with different designs. One says “the Prosecutor verse the Felon”, while another sports the phrase “Make America Laugh Again.”

Robinson tells me that he wants to see which candidate is on their toes and who came prepared for the debate tonight. He said he expects Donald Trump will try to degrade Harris and rattle her.

"She’s a prosecutor, she’s going to recover,” he says confidently.

Sam Cabral
Reporting from Washington

Image source, Getty Images

Public polling nationwide and in swing states shows that many voters still do not know enough about Kamala Harris and what she stands for, and many believe Donald Trump is closer to the centre of the political spectrum than she is.

That means the debate is a major opportunity for Harris to re-introduce herself to voters and define who she is - but it is also an opportunity for Trump to shape voters' perceptions of her.

And many of his high-profile supporters are making the case in public interviews that the Republican candidate should avoid critiquing Harris over her intelligence, looks or other personal attributes and instead focus on policy critiques.

In weekend media appearances, former UN Ambassador Nikki Haley - who opposed Trump in the Republican primary but has since endorsed him - said he and his running mate, JD Vance, "need to change the way they speak about women".

"You don't need to call Kamala dumb. She didn't get this far, you know, just by accident," she told Fox News.

"The bottom line is, we win on policies. Stick to the policies, leave all the other stuff. That's how he can win."

Tom Bateman
reporting from Johnstown, Pennsylvania

Image source, Tom Bateman / BBC

Kelly and Joseph Graham will watch tonight to see how the rivals promise to bring down the cost of living, which spiralled under the Biden administration.

Sitting on their porch here in Johnstown, Pennsylvania, their handwritten sign for “EGGS 2 DOLLARS” swings in the yard: The couple bought their own chickens amid the difficult economic conditions here.

Kelly says of Trump: “He knows how to straighten things out. He's a businessman, you know, and our economy is a mess. Our food is awful, the prices are terrible.”

Opinion polling puts Pennsylvania on a knife-edge making it a critical swing state. But the spread of the candidates’ support is uneven. These rural areas overwhelmingly back Trump while Harris is well ahead in the cities.

And there’s another divide - among men, who disproportionately back Trump, and women, more likely to favour Harris. This brings one of Trump’s vulnerabilities into focus: His record on abortion rights, an issue about which Kelly and Joseph differ.

“I don’t believe in abortion,” says Joseph.

Kelly counters: “That's a woman's right. That is not up to the government to decide… that is up to each individual, not the state or the government.”

Bernd Debusmann Jr
Reporting from Philadelphia

Image source, Getty Images

Kamala Harris said that she expects Donald Trump to "speak a lot of untruths" from what she termed a "really old and tired playbook".

"There's no floor for him in terms of how low he will go," she said in a pre-recorded interview with US radio personality Rickey Smiley on Monday. "We should be prepared for the fact that he is not burdened by telling the truth."

Harris added that she believes Trump "tends to fight for himself, not for the American people, and I think that's going to come out during the course of the debate."

She added that Trump "is going to lie", and referenced previous comments he made about both Barack Obama and Hillary Clinton.

"We should expect some of that might come out," Harris said.

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Throughout the campaign season, the BBC speaks to voters to get their opinions on the leading candidates, big issues and news events of the day. You can be part of this project: We’re looking for voters with unique perspectives to join our panel.

Do you live in a swing state? Are you voting for the first time? Did you recently become a US citizen? We want to hear from you.

Contact us through this form to be considered. Tell us about yourself, which issues matter to you and how you’re feeling. We may contact you for an interview for our future coverage.

Rachel Looker
US reporter

The last time US presidential candidates met on stage, they traded barbs and personal takedowns in a debate that upended the 2024 campaign.

Tuesday's debate represents an opportunity for a do-over for both parties and the consensus among voters is clear: they want more policy and less political sparring.

The BBC spoke to voters from across the political spectrum. Here's what a few of them are hoping to see unfold.

Hear from these voters and others about what they say they want to see when Harris and Trump face off for the first time in Philadelphia.

Image source, Getty Images

Kamala Harris faced weeks of criticism from Republicans for taking on the Democratic presidential nomination in July and not sitting down for an interview with media.

On 29 August, she did. Harris sat for her first major interview with CNN's Dana Bash, alongside running mate Tim Walz.

While not generating any major headlines, the interview did touch on some of her policy stances.

Harris was pressed on why her policies on immigration and climate have changed since she ran for president in 2019.

"I think the most important and most significant aspect of my policy perspective and decisions is my values have not changed," she responded.

Asked about her reversal on banning fracking, a technique for recovering gas and oil from shale rock, she said she was confident US climate targets could be met without such a ban.

Harris was asked about the war in Gaza, and re-iterated the White House's position that both Israel and Hamas must "get a deal done", and that the Palestinians deserve to have their own country neighbouring Israel.

And Harris said she would include a Republican in her presidential cabinet.

You can read more about the interview here.

Image source, Reuters

It wouldn't be American politics without a bit of intrigue, and there is certainly some between one presidential candidate and the network running the debate.

“ABC is probably the worst in terms of fairness,” Trump declare in a Fox News interview earlier this month.

Complaints of bias are part of Trump’s pre-debate playbook. Before the CNN debate in June, Trump and his allies warned the showdown was a “hostile environment” for the former president.

But in this case the feud goes deeper, with Trump embroiled in a legal battle with ABC.

He is suing the network and host George Stephanopoulos - who is not a debate moderator - for defamation over on-air comments made by Stephanopoulos earlier this year.

In March, Stephanopoulos asked congresswoman Nancy Mace in an interview why she backs Trump despite him being found "liable for rape", as well as other similar remarks.

Last year, a New York civil court found Trump sexually abused writer E Jean Carroll in 1996 but did not say Trump had raped her.

Stephanopoulos has not backed down from his remarks. This summer a motion to dismiss the lawsuit was thrown out.

Bernd Debusmann Jr
Reporting from Philadelphia

Ahead of tonight's debate, officials from ABC News have largely shied away from the question of whether moderators David Muir and Linsey Davis will fact-check Donald Trump and Kamala Harris in real-time during the event.

ABC political director Rick Klein said in a New York Times interview on Sunday that Muir and Davis are there to "facilitate a discussion" that ultimately "belongs to the candidates".

"I don't think it's a 'yes' or 'no' proposition," Klein said of the possibility of fact-checking. "We're not making a commitment to fact-check everything, or fact-check nothing, in either direction".

"We're there to keep a conversation going, and to facilitate a good solid debate, and that entails a lot of things in terms of asking questions, moving the conversation along, making sure that it's civilised."

Image source, Getty Images

The presidential debate between Kamala Harris and Donald Trump will be moderated by ABC anchors David Muir and Linsey Davis.

Both journalists have extensive backgrounds in US political reporting.

Davis moderated Democratic presidential debates in 2019 and 2020. And Muir has moderated multiple Democratic and Republican presidential primary debates.

Muir - the anchor and managing editor of ABC World News Tonight - has previously interviewed Trump, and had a joint interview with Joe Biden and Harris in the weeks before the 2020 election. Davis has previously interviewed Harris.

The ABC network, although not specifically Davis and Muir, has been criticised by Trump of being biased in the weeks leading up to the debate.

Kayla Epstein
reporting from New York

The candidates appear to have holed up with their teams in recent days to prepare for tonight’s showdown.

Campaigns regularly hold simulations in which they have aides or political allies stepping in to play the role of an opponent.

The New York Times reports, external that Kamala Harris spent several days preparing with her team in Pittsburgh.

The campaign has reportedly built a facsimile of the actual debate stage and an advisor is playing the role of Trump.

Trump’s team, on the other hand, is trying to focus on “policy time”. the Times reported.

A more restrained version of Trump appeared at last June’s debate against Joe Biden, a far cry from the politician who interrupted Biden so often in a 2020 debate that Biden told him to “shut up, man.”

It remains to be seen which version will show up tonight, as - much to his allies' furstrations - Trump has recently struggled to stick to a discussion of policy.

Image source, Reuters

During a pivotal debate in the 2020 US presidential election, one candidate seemed to dominate the stage.

They interrupted their rivals at strategic moments, sometimes speaking over them. They directly confronted an opponent, Joe Biden, generating headlines for days and had critics questioning whether they had breached some sort of unspoken political decorum.

That candidate, however, wasn’t Donald Trump. It was Kamala Harris.

Harris is once again take to the debate stage tonight. Debates have played a major role in her political career, from her run for California attorney general to her ascent to the vice-presidency.

It’s clear that Harris knows when to seize the spotlight, but also when to stand by as a rival administers a self-inflicted blow.

In her earliest debate appearances, she found success by letting her opponents dismantle themselves. She has also proved adept at claiming the floor for herself, even amid a crowded field.

Read more about Harris’s debate style here.

Bernd Debusmann Jr
Reporting from Philadelphia

Image source, Getty Images

Yesterday, Trump campaign officials and their surrogates held a media call in which they outlined their expectations for today's debate and offered glimpses into the former president's strategy against Kamala Harris.

During the call, Trump campaign senior advisor Jason Miller said that Trump's overarching message will be that Harris "owns every failure" of the Biden administration, arguing that she played a key role in every decision taken over the last nearly four years.

"You can't talk about turning the page when you're the one who created our current nightmare," Miller said.

Two key Trump supporters - Florida Representative Matt Gaetz and former Hawaii Representative Tulsi Gabbard - laid out a number of attack lines that Trump is likely to use against Harris, including the US-Mexico border, crime and a perceived lack of foreign policy successes.

"President Trump is going to tie her to that record," said Gaetz, who called the vice-president a "dangerous, radical liberal" who faces high stakes tonight.

"She has been bubble wrapped... since securing the nomination," he said. "A lot of people haven't seen her pressed."