Kamala Harris and vice president candidate pick Tim Walz make first appearance together

The Minnesota governor was confirmed as Ms Harris' pick on Tuesday and just hours later the pair appeared together at a rally in Philadelphia.

Since the announcement, Team Harris-Walz said it has raised more than $20m (£15.8m).

Speaking to a raucous crowd of more than 10,000 at Temple University, Mr Walz introduced himself to Democratic voters and the wider American public.

He described growing up in a small town in Nebraska, serving in the US Army National Guard, becoming a social studies teacher and a football coach before getting into politics.

Describing his time in Congress, Mr Walz said he learned the art of compromise, working across parties "without compromising my beliefs".

The plain-speaking politician seemed to go down well with the newly energised Democratic base.

In choosing the 60-year-old, Ms Harris is elevating a Midwestern governor, military veteran and union supporter who helped enact an ambitious Democratic agenda for his state, including sweeping protections for abortion rights and generous aid to families.

The selection also indicates Ms Harris's hopes to shore up her campaign's standing across the upper Midwest - a critical region in presidential politics.

Two states in the region, Michigan and Wisconsin, voted for Mr Trump in 2016. While Mr Biden was able to reclaim both states in 2020, it was with a margin of just 2.78% and 0.63% respectively.

During the rally, Mr Walz shared the story of how he and his wife used IVF to conceive their daughter, Hope.

He contrasted the Democrat's support of wider access to healthcare with a Republican party he said was no longer interested in protecting American freedoms.

Mr Walz also commended his vice-president nominee rival Josh Shapiro in the opening remarks of his speech as he railed against Donald Trump, who he warned "would only take us back".

"His running mate [JD Vance] shares his dangerous and backward agenda for this country... and I've got to tell you, I can't wait to debate the guy."

Earlier, Ms Harris, 59, said: "Tim Walz was the kind of teacher and mentor that every child in America dreams of having, and that every kid deserves.

"That is the kind of vice president America deserves."

She listed off Mr Walz's accolades, including his apparent skills as a marksman winning a bipartisan Congress shooting contest year after year.

She added: "We are the underdogs in this presidential race. But we have the momentum, and I know exactly what we are up against.

"This campaign, our campaign, is not just a fight against Donald Trump.

"Our campaign, this campaign, is a fight for the future."

The site of their first rally, in Pennsylvania, is seen as perhaps the most critical state in what is expected to be a heated election between the the two major parties.

Mr Harris's running mate pick drew praise from ideologically diverse lawmakers including progressive representative Alexandria Ocasio-Cortez and independent senator Joe Manchin.

The news was also praised by former president Barack Obama, who described how "Tim's signature is his ability to talk like a human being and treat everyone with decency and respect".

-SKY NEWS