Democratic vice presidential running mate, Kamala Harris, listens to presidential nominee Joe Biden's speech during their first press conference in Wilmington, Delaware on Wednesday. Photo: AFP

Joe Biden and Kamala Harris launched their joint White House bid Wednesday, with the newly-minted vice presidential nominee saying Americans are "crying out for leadership" to overcome the triple crisis of a pandemic, racial injustice and a ravaged economy.

Making their first appearance as running mates, before a small crowd of reporters and staffers at a Delaware high school closed to the public due to coronavirus concerns, the Democratic duo vowed to end Donald Trump's presidency and, in Biden's words, "rebuild this country." 

"Everything we care about," said Harris. "It's all on the line."

A formidable 55-year-old US senator from California and a daughter of immigrants, Harris has already made history as the first woman of color tapped for a major party presidential ticket.

Describing a country at the crossroads, she left little doubt of her determination to go on the attack, saying Trump "just isn't up for the job" and has left the nation "in tatters."

"America is crying out for leadership, yet we have a president who cares more about himself than the people who elected him," said Harris.

Despite the awkwardly intimate setting, a far cry from the typical campaign rollout featuring an audience of thousands, Harris appeared telegenic and confident in her first speech as vice presidential nominee - for which she and Biden both arrived wearing face masks.

"The case against Donald Trump and Mike Pence is open and shut," said the former California attorney general as she assailed the president's "failures of leadership" on containing the deadly pandemic and an economy hobbled by measures to fight the contagion.

The daughter of Indian and Jamaican immigrants to the US sought to tap into the nationwide upheaval over police violence and racial disparities.

"We're experiencing a moral reckoning with racism and systemic injustice that has brought a new coalition of conscience to the streets of our country demanding change," she said in a statement.

For Biden - who leads Trump in most national polls and in swing states like Florida and Wisconsin despite conducting the campaign mostly from his Wilmington, Delaware home - his VP reveal marks a crucial moment as he aims to build a broad coalition of voters to defeat Trump.

Biden spoke of why he chose Harris as his partner, stressing she was a tough and experienced legislator who is "ready to do this job on Day 1."

AFP