Kamala Harris addresses nation after conceding election to Donald Trump

US Vice President Kamala Harris has delivered her first public remarks since conceding the presidential election to Donald Trump.

Walking out to Beyonce's "Freedom," her campaign song, Harris smiled and waved at a large outdoor crowd, telling them "My heart is full today. Full of gratitude for the trust you have placed in me."

"The outcome of this election is not what we wanted," she said, "not what we fought for, not what we voted for, but hear me when I say: The light of America's promise will always burn bright as long as we never give up, and as long as we keep fighting."

With four states yet to be called, Trump has been projected to win 292 Electoral College votes, well clear of the 270 needed to take the presidency.

Harris' campaign had organised an election night victory party at her alma mater of Howard University in Washington, DC, but as the returns steadily turned against her and swing state after swing state was called for Trump, the crowd began to leave and the event was called off by her campaign co-chair.

In her address, which she delivered on the Howard campus, Harris said she was "so proud of the race we ran, and proud of the way we ran it," celebrating the "enthusiasm and joy" her supporters had shown as they fought to defeat Trump.

"I know folks are feeling and experiencing a range of emotions right now. I get it. But we must accept the result."

Some in the crowd booed her as she described calling Trump to let him know she would be helping with the presidential transition — but Harris was cheered when she insisted that the peaceful transfer of power was crucial to the survival of democracy.

"A fundamental principle of American democracy is that when we lose an election, we accept the results...at the same