The US President Joe Biden commenced his 2024 Presidential campaign on Friday with a major speech warning that democracy is at risk from Donald Trump, three years after the deadly January 6 US Capitol attack.

The 81-year-old will say the fight for democracy is a "sacred cause" in his speech, a day before the third anniversary of the Capitol assault by a pro-Trump mob trying to overturn Biden's 2020 election win, reports AFP. 

Either trailing or neck and neck with Trump in recent polls, the Democrat will frame his likely Republican rival as a threat to the nation in the address near the historic US independence war site of Valley Forge in Pennsylvania.

Biden did not speak to reporters as he left the White House on Friday aboard the presidential helicopter, Marine One.

But campaign manager Julie Chavez Rodriguez said Biden's election pitch four years ago that he was leading a "battle for the soul of America" was more relevant than ever.

"The threat Donald Trump posed in 2020 to American democracy has only grown more dire in the years since," she said in a statement.

The campaign push will continue Monday when the president visits a South Carolina church where a white supremacist shot dead nine Black parishioners in 2015.

Bd-pratidin English/Lutful Hoque