Image source, US Pool

Kamala Harris thanks the crowd for its "warm welcome", as well as Pennsylvania Governor Josh Shapiro for being in attendance, calling him an "incredible leader".

"Together with Josh Shapiro we will win Pennsylvania," she says.

Shapiro was a top contender to be her running mate, but Harris chose Tim Walz instead.

Harris reminds the crowd that she launched her campaign for president just two weeks ago, saying that it has been a "whirlwind" since then.

She has since secured the Democratic Party's nomination, adding that "now we have some work to do".

Vice-President Harris has just walked out to roaring applause alongside her running mate Tim Walz, to an audience of supporters at Temple University in Philadelphia.

We'll also hear from Walz himself shortly.

Stay with us as we bring you live text updates, and you can also watch the rally at the top of this page.

No hard feelings for Shapiro after missing out on VP pickpublished at 22:48 British Summer Time 6 August

22:48 BST 6 August

Anthony Zurcher
North America correspondent, in Philadelphia

Josh Shapiro, the popular Democratic governor here in Pennsylvania, just got an extended, enthusiastic ovation from this Philadelphia crowd.

After the cheering subsided, the man who was in Kamala Harris’s vice-presidential short list said he was going to continue to pour his “heart and soul” into being governor. He pledged to “work my tail off” to help Harris and her new running mate, Tim Walz, win in November.

Shapiro went on to praise Walz, saying he was a “great man” and a “dear friend”.

If there were any hard feelings, they were not apparent on this night.

Image source, Getty Images

Pennsylvania Governor Josh Shapiro - who was one of the finalists for Kamala Harris's running mate - is speaking to the packed crowd in Philadelphia.

He's talking about the Trump presidency, and tells the crowd "we're not going back," which has become a key line of the Harris campaign.

Shapiro is applauding Tim Walz being chosen as Harris's VP pick, calling him an "outstanding governor" and a "great patriot".

Rachel Looker
Reporting from Pennsylvania

With Walz about to make his first appearance as a vice-presidential candidate in Philadelphia, one expert tells me it marks an opportunity for the Harris campaign to present the Minnesota governor to Pennsylvanians who don't know much about him.

“In Pennsylvania, Walz is not super well known so the campaign has an opportunity to kind of sell and set up a profile of Walz," Dan Mallison, an associate professor of public policy and administration at Penn State University, says.

Mallison says Pennsylvania Governor Josh Shapiro, who is speaking at the rally and endorsing the Harris-Walz ticket, will play a key role in delivering the key battleground state for the Harris campaign.

“It’s one of those collection of states that’s really important for whoever is going to win the presidential election and the electoral college,” he says.

Anthony Zurcher
North America correspondent, in Philadelphia

Image source, Getty Images

The arena here at Temple University is now packed to the rafters with Democratic supporters.

They’re waving signs that read “When we vote, we win” and “Kamala” in red, white and blue, while hip-hop music thumps over the speakers.

Pennsylvania’s two senators, John Fetterman and Bob Casey, just gave warm-up speeches.

Fetterman called the Republican ticket “weird, weird, weird dudes”.

Harris and her newly chosen running mate, Tim Walz, should be taking the stage soon.

Image source, Getty Images

The countdown is on - Harris and Walz will appear in person for the first time together in around 10 minutes.

It's been a whirlwind day for the Minnesota governor, who has gone from a lesser-known but beloved Midwestern leader to a major party's vice-presidential candidate in less than 24 hours.

We've seen a few campaign videos from social media accounts for Harris and Walz, but this will be the first time the two campaign in person since the announcement this morning.

We're covering the rally at Temple University live. You can follow along with our live blog and by clicking watch live at the top of this page.

Tim Walz is not a household name in American politics and until recently wasn't even considered a frontrunner to be Kamala Harris's pick as vice-president.

But after days of speculation, Harris has chosen Walz as she looks to gain support among working class and progressive voters.

What does his selection tell us about the Democrats' strategy to retain the White House in November?

• You can listen to this episode on BBC sounds

Caitlin Wilson
Reporting from Washington, DC

Presidential nominees want their running mates to help them win the election - that calculation might go beyond policy agreements and professional compatibility.

It might also matter where that VP pick is from. Tim Walz is a popular governor in his home state of Minnesota - can that popularity translate across the Midwest region, which includes the key swing states of Michigan and Wisconsin, to bring in votes for Kamala Harris and the Democrats?

Presidential candidates might see a boost "of three or four points" in their home state, according to Christopher Warshaw, a political science professor studying public opinion and state and local politics at George Washington University.

That modest advantage drops, however, when it comes to vice-presidential candidates. They might only bring an extra one or two points to the ticket regionally, Warshaw says.

Image source, Getty Images

But “in this era of super-close elections, giving yourself a one-point advantage in a swing state is not unimportant”, he adds.

There is evidence that Barack Obama being from Illinois helped him pick up votes across the Midwest in 2008, Warshaw says.

But the most important lesson when it comes to picking a vice-presidential nominee? Warshaw warns: “From an electoral perspective, you really don’t want to shoot yourself in the foot” with a candidate who will perform poorly nationally just to pick up those few points in their home state.

Walz shared a campaign video to social media hours after accepting the role of Harris's running mate.

"Growing up, I learned to be generous toward my neighbors, compromise without compromising my values, and to work for the common good," he wrote in a post on X, formerly Twitter.

"Kamala Harris and I both believe in that common good - in that fundamental promise of America. We’re ready to fight for it. And like she says: when we fight, we win."

In the clip, he emphasises his Midwestern background, his teaching experience and his political career highlights.

Image source, Getty Images

It's been another busy day in US politics. Here's a recap if you're just joining us:

• This morning, Kamala Harris announced Minnesota Governor Tim Walz as her running mate
• Polls find that he's a new face for many Americans, but he also has some dedicated fans - you can read a profile on Walz here
• Harris will formally introduce Walz at a rally in Philadelphia in the next hour, before the two embark on a multi-state tour to court swing voters
• The choice was met with widespread praise from Democrats of all stripes. President Biden weighed in, saying the Harris-Walz ticket would be "a powerful voice for working people and America's middle class"
• Former President Trump and his running mate JD Vance cast Walz as a "far-left radical" over some of his more progressive policy positions
• Republicans criticised his response to 2020 racial justice protests in Minneapolis as they test out attack lines
• Earlier, Vance addressed supporters in Philadelphia, where he said he "absolutely" wants to debate Walz but only after he is "officially the nominee", questioning whether the Democrats would "pull a switcheroo" and change vice-presidential candidates before November

Senator Amy Klobuchar, who was a 2020 presidential candidate and a long-rumoured VP candidate for Joe Biden, has lauded Kamala Harris for picking Walz, calling him a "fantastic choice" and as "humble as they come".

Appearing on MSNBC, Klobuchar, who represents Minnesota, says Walz will bring unique experience to the ticket, including a background in the military and working on agricultural policy when he served in the House.

She pushes back against Republicans who have criticised Walz's handling of the 2020 racial justice protests in Minneapolis, emphasising that he rejected calls to reduce police funding.

His folksy quips - which have earned him fans on social media - are genuine, she says, noting that Walz often eschews notes and scripts.

He's "a burly football coach, which I think is a great description of what we need right now to take on Donald Trump", she says.

Image source, Reuters

We've just had word from the traveling press pool that Kamala Harris arrived at Temple University's Liacouras Center at 16:00 local time.

The pool noted that the venue is about half full at the moment, but rapidly filling up ahead of the 17:30 ET (22:30 BST) rally.

Many members of the crowd are wearing blinking red, white and blue wristbands that light up.

Among those already there is Philadelphia's Mayor, Cherelle Parker, who ignored questions about Pennsylvania Governor Josh Shapiro, one of the former top contenders for the Harris ticket.

The Harris campaign released a video this afternoon of Kamala Harris calling Tim Walz to extend a job offer.

"Listen, I want you to do this with me. Let's do this together. Would you be my running mate?" she asks him.

"I would be honored, Madame Vice President," he replies. "The joy that you're bringing back to the country, the enthusiasm that's out there, it would be a privilege to take this with you across the country."

Vice-President Harris has arrived in Philadelphia accompanied by her husband Doug Emhoff, disembarking Air Force Two at about 15:38, according to traveling pool reporters.

She ignored questions from the press about why she chose Tim Walz as her running mate.

The motorcade began driving at 15:41, just minutes later.

The next we are likely to see from Harris is at her rally a little later today.

Stay with us for more updates.

Rachel Looker
Reporting from Pennsylvania

I spoke with Joan Swantek and Tony Toro - two voters from the Philadelphia suburb of Lansdale - who told me they were rooting for Pennsylvania governor Josh Shapiro to be the vice presidential pick.

But they both agreed that Kamala Harris’ decision to choose Tim Walz over Shapiro won’t cost her the race in the swing state of Pennsylvania - which has a consequential 19 electoral votes.

“I think she’s going to win,” Toro says.

Both Toro and Swantek say they plan on voting for Harris in November.

Another voter who spoke to me at a diner outside of Philadelphia said she was unsurprised Harris didn't pick the Pennsylvania governor.

"I don't think she knows him," Fran Zimmerman of North Wales, Pennsylvania, told me. "She's West Coast; he's East Coast."

But Zimmerman also said she intended to vote for Harris, regardless of who she chose as her running mate.

"They really say that vice presidents aren't that important," she said.

We've spoken to a number of Democratic voters across the US today to hear what they think about Harris' vice-presidential selection of Walz - here's what they had to say.

Illinois voter Annie Tye, 43, said Harris choosing Walz was the "smart thing" to do.

"Somebody who's a gun guy could bring in some of the people who are really hesitant to vote for an anti-gun liberal," Tye said, "but Walz has a hunting background and at one point had a positive rating with the NRA."

Oklahoma voter Isaac Chandler, 30, said he was drawn to Walz because he offers a more inspirational message.

"It's really what we need right now in this country," Chandler said. "The Harris-Walz ticket is more representative of the wider American public than the Vance-Trump ticket: this ticket makes me feel a lot more inspired for this election."

Anthony Zurcher
North America correspondent, in Philadelphia

Image source, Anthony Zurcher / BBC

The basketball arena here at Temple University is starting to fill up, although it’s still around two hours from the scheduled start of the rally. A few upper sections are already packed with what looks like local university students.

Many are wearing blue light-up wristbands – the kind often seen at big rock concerts – that were handed out at the door.

They all cheered when the jumbo screens played a series of video clips of Kamala Harris and Tim Walz, set to what has become the campaign’s theme song – Freedom by Beyonce.

Image source, Anthony Zurcher / BBC

Image source, Getty Images

We're 91 days out from the presidential election and the media coverage has understandably all been about Kamala Harris picking Tim Walz as her running mate.

But there's also news coming from Donald Trump, who just shared on Truth Social that he will be doing an interview on Monday night with the richest man in the world, Elon Musk.

Musk recently endorsed Trump and has started getting involved in fundraising efforts for the Republican nominee.

Details of when and where the interview will be held have not been confirmed. But it's possible it would be on X, Musk's social media platform.

It wouldn't be the first time Trump has been interviewed on X. An interview with Tucker Carlson was livestreamed on the platform at the same time as the first Republican debate last year, which Trump skipped.

Bernd Debusmann Jr
Reporting from the White House

Mindful of the law, White House Press Secretary Karine Jean-Pierre has so far carefully skirted around questions about Joe Biden's response to the selection of Walz as Harris's running mate.

Asked about any similarities she sees between the president and Minnesota's governor, Jean-Pierre says only that Biden "appreciates" Walz for his work in Minnesota and his "impressive background".

"He is someone with values that the president obviously has as well," she adds.