Madeline Halpert
Reporting from New York

Myself and some of tonight's debate reporting team have arrived at the CBS studios in Manhattan, where the event's being held.

Outside, it's a typical day in the city, except for vans and trucks passing by advertising for either Donald Trump or Kamala Harris.

I saw three vans plastered with photos of Trump and his running-mate, JD Vance, along with that previous quote from Vance: "I'm a never Trump guy". Remember, Vance was an ardent critic of Trump during the 2016 US election, but has since said he changed his mind.

A man is also driving a truck around the block, over and over, adorned with Trump-Vance flags.

Image source, Getty Images

With Iran's decision to launch a missile attack on Israel having just been described at a US State Department briefing as "a significant escalation", it seems increasingly likely that the Middle East conflict could be brought up at tonight's debate.

At the briefing, National Security Adviser Jake Sullivan said US military forces in the region had helped Israel to defeat the attack - and the Biden administration was now consulting with Israel on a response.

The race for the White House is being keenly watched in Middle East, the BBC's Paul Adams reported following the presidential debate between Kamala Harris and Donald Trump last month. Palestinians, he said at the time, are deeply sceptical about Trump - but dismayed by the Biden administration’s inability to stop the war in Gaza, are possibly inclined to see Harris as the lesser of two evils.

This afternoon, on a campaign visit to Wisconsin, Trump warned that the world "is close to global catastrophe" due to the conflict and accused Biden of being a "non-existent president" and Harris a "non-existent vice president" on the issue.

• For more on what's happening in the Middle East, follow our other live page which is taking in the region's latest updates and analysis from our teams on the ground

Image source, Reuters

As second in command, vice-presidents have roles as in terms of advisers and as the presiding officer of the Senate.

They have the only power to break a tie vote in the Senate - something the sitting VP Kamala Harris said she exercised to pass the Inflation Reduction Act in 2022.

First in the presidential line of succession, VPs are also transferred presidential powers when a sitting commander-in-chief is out of action. In 2021, Harris became the first woman to be put in such a position when Joe Biden underwent a regular health check under anaesthesia.

Over the years, the responsibilities of vice-presidents have grown, taking a more active role in the executive branch and serving as top aides to the president.

With all eyes turning to New York ahead of tonight's vice-presidential debate, you may be wondering where you can watch the head-to-head as it unfolds.

Here on the BBC, we'll bring the action to US, international and UK audiences in a variety of places, including:

• The BBC News channel
• The BBC News website and app
• BBC One and iPlayer
• FAST/CTV platforms in the US
• And remember, we'll also show the debate live right here at the top of this page

The coverage will begin at 20:00 ET (01:00 BST) and go on for about four hours.

On the ground at the debate, the BBC's team includes North America editor Sarah Smith and correspondent Anthony Zurcher, whose handy analysis you'll be able to see before, during and after the debate.

Stick with us as we continue our build-up.

Over in New York, a small group of climate protesters have been handcuffed and led away by police outside tonight's debate venue, CBS Broadcast Center.

They say they want moderators to ask JD Vance and Tim Walz about climate change, and were seen holding a banner that reads "Big oil caused Hurricane Helene" - the storm that swept over the US's south-east at the weekend and killed at least 135 people.

The Sunrise Movement, a climate change activist group, says some of its members were arrested. Video online shows one person being handcuffed and led away. Police are yet to comment.

• For context: While scientists say it’s difficult to link any one event to climate change, the frequency and severity of various extreme weather patterns is on the rise because of climate change. You can read more about how climate change worsens heatwaves, droughts, wildfires and floods here.

Image source, Getty Images

Tonight's vice-presidential debate comes three weeks after Donald Trump and Kamala Harris faced each other in Philadelphia, Pennsylvania - a key swing state.

Many of the issues that the presidential nominees clashed over are likely to come up tonight as well.

Polls suggest voters care most about the economy, inflation, abortion rights and immigration.

Walz may target Vance on some of the false claims he's made about Haitian migrants in Springfield, Ohio eating people’s pets - something Trump brought up in his debate with Harris.

Meanwhile, Vance could question Walz about his military history or his wife’s use of fertility procedures - both are attack lines he's used before.

Each candidate will also likely make a push for why their running mate should be the next US president.

Tim Walz and JD Vance will debate an array of important issues later - including immigration and the US economy.

BBC Verify's fact-checking team will be on hand throughout, listening out for key claims made on either side, as explained in the below clip.

Mike Wendling
Reporting from Washington DC

Image source, Getty Images

“I’m a ‘never Trump’ guy. I never liked him.”

That was JD Vance in 2016, just after the publication of his memoir Hillbilly Elegy catapulted him to fame.

But now the 40-year-old first-term senator from Ohio is Trump’s vice-presidential running mate - and, by extension, an early frontrunner for the Republican presidential nomination in 2028.

Vance had long been whispered about as a political candidate, and he saw an opportunity when Ohio’s Republican Senator Rob Portman decided not to run for re-election in 2022.

With a reliably conservative voting record, relative youth and Midwestern roots, Republicans hope he will appeal to their base - particularly in the key swing states of Wisconsin, Pennsylvania and Michigan.

In between bursting into prominence as a best-selling author and running for office, Vance not only underwent a religious conversion - he was baptised as a Catholic in 2019 - but also a fundamental political transition.

From a never-Trumper, remaining a sceptic of the former presenter as late as 2020, he’s now a firm leader inside the Make America Great Again camp - and has signed up almost entirely to Trump’s agenda.

• Learn more about Vance’s background, including what he's said during the campaign trail

Sam Cabral
US reporter

Image source, Reuters

With one viral line on cable TV - "these guys are just weird" - Tim Walz vaulted into contention for the job of Kamala Harris's running mate.

The 60-year-old brings with him a folksy, plain-spoken and sharp-tongued approach to taking on the Republican opposition.

He also comes with a compelling resume - a public school teacher, football coach and National Guardsman before he entered politics. As a coach at Mankato West High School, Walz helped build up an American football programme that led the school to its first state championship.

Former members of the team appeared on stage when Walz addressed the Democratic National Convention in Chicago. He leant heavily into American football metaphors during his address to the party faithful, saying: "We're driving down the field, and boy, do we have the right team.”

Walz won the 2018 Minnesota governor's race by more than 11 points but his first term was overshadowed by the Covid pandemic and the killing of George Floyd by a police officer in Minneapolis. The governor won re-election, albeit by a narrow margin, and his second term has overseen a busy period with Democrats controlling the state legislature by a single seat.

• Get up to speed with Tim Walz's background, including his views and beliefs

VP debates rarely matter - this one is differentpublished at 17:18 British Summer Time 1 October

17:18 BST 1 October

Anthony Zurcher
North America correspondent

In a tight race that could be decided by tens of thousands of votes in a handful of states, every opportunity to generate positive attention and political momentum is precious.

At the very least, tonight's debate will be a fascinating contrast between two men with very different styles and political beliefs, and two campaigns with distinct strategies for winning the White House.

Donald Trump announced his selection of Vance back in July, just a day after his near-assassination. The former president was riding high in the polls, and his pick of the 40-year-old Ohio senator was viewed not only as a play to the white working class in the industrial Midwest - a key demographic in a region that is a top electoral battleground - but also as a way to establish his political legacy.

If Vance was a front-runner to be Trump’s running-mate, Walz’s path to the Democratic number-two spot was considerably more unlikely. The governor of Minnesota was not a leading contender for the job but his viral appearances on television, deriding Republicans as “weird”, and his ability to defend liberal policies in moderate-friendly language won Harris over.

During the debate, Vance is likely to continue to hammer Democrats on the economy, immigration and crime - areas where polls show Trump and the Republicans are favoured. Walz may counter by highlighting Vance’s past controversial statements - on Ohio Haitians and his derisive remarks about Democratic women who don’t have children being “childless cat ladies”.

With no further presidential debates scheduled this year, the running-mate face-off could be the last chance for American voters to see the two tickets represented in direct contrast before they cast their ballots.

• You can read more of Anthony Zurcher's analysis here

The head-to-head will be held on Tuesday night at 21:00 ET (02:00 BST) in New York City at the CBS Broadcast Center.

It will be broadcast on CBS Television Network and livestreamed on platforms where CBS News 24/7 and Paramount+ are accessible. You'll also be able to watch it at the top of this page.

The 90-minute debate will be moderated by CBS Evening News anchor Norah O'Donnell and chief foreign affairs correspondent Margaret Brennan.

As we've said already, the BBC will have a team of reporters in NYC and in DC providing analysis, fact checks and reactions as part of our coverage.

Sam Hancock
Live page editor, in Washington DC

There are just five weeks to go until Americans head to the polls to vote for their next president: Donald Trump, for the Republicans or Kamala Harris, for the Democrats.

With each of them comes a vice-presidential running mate: JD Vance, for Trump; Tim Walz, for Harris. And tonight it's these two who'll be under the spotlight as they come together to debate for the first - and only - time before election day on 5 November.

We know that Vance has been preparing with Republican congressman Tom Emmer, his wife Usha and senior Trump adviser Jason Miller - while Walz has been preparing with Transportation Secretary Pete Buttigieg, standing in as Vance.

The 90-minute face-off will air tonight at 21:00 ET (02:00 BST) in New York, where we'll have a team of reporters at the debate itself - which you'll be able to watch at the top of this page. In DC, there'll be more of us to provide analysis, fact checks and reactions.

Before then we'll bring you the build-up you need, including what to look out for and the latest news lines. Stay tuned.