Kamala Harris has said “we must accept the results of this election” as she encouraged supporters to continue fighting for their vision of the country after her loss to Donald Trump.

The Democratic vice president said the battle would continue “in the voting booth, in the courts and in the public square”.

“Sometimes the fight takes a while,” she said. “That doesn’t mean we won’t win.”

Ms Harris delivered her remarks at Howard University in Washington DC, her alma mater and one of the country’s most prominent historically black schools, in the same spot where she hoped to give a victory speech.

“While I concede this election, I do not concede the fight that fuelled this campaign,” she said.

Her running mate, Minnesota governor Tim Walz, was in the audience along with Nancy Pelosi, the former House of Representatives speaker.

Before her speech, Ms Harris called Mr Trump to concede the election and congratulate him on his victory. She said: “We will engage in a peaceful transfer of power.”

Ms Harris, once viewed as a potential saviour for the Democratic Party after Joe Biden’s re-election campaign stalled, is reckoning with a profound rejection by US voters in the presidential election.

She trailed in every battleground state to Mr Trump, a man she described as an existential danger to the country’s foundational institutions.

Mr Trump appears on track to win the popular vote for the first time in his three campaigns for the White House — even after two impeachments, felony convictions and his attempt to overturn his previous election loss.

Mr Biden plans to address the election results on Thursday. The White House said he spoke with Ms Harris and Mr Trump on Wednesday, and he invited the president-elect to meet him soon.

David Plouffe, a top Harris adviser, said campaign staff “left it all on the field for their country”.

“We dug out of a deep hole but not enough,” he said. “A devastating loss.”

In a bitter footnote for Ms Harris, as the sitting vice president she is expected to oversee Congress’s ceremonial certification of the election.

It is the same role Mike Pence played four years ago, when Mr Trump directed his supporters to march on the US Capitol. Although critics said the violent insurrection crystallised Mr Trump’s threat to US democracy, that ultimately did not dissuade voters from electing him again.