Washington | President Joe Biden on Tuesday launched his reelection bid with a call for Americans to give him more time to "finish the job, less than three years after he defeated his predecessor Donald Trump to become the oldest president in US history.

Biden, the 80-year-old Democrat, made the announcement in a three-minute promotional video that begins with a one-word pitch: Freedom.

Biden argues that abortion rights, the defence of democracy, voting rights and the social safety net will be among the most important issues on the ballot in 2024.

"Every generation of Americans has faced a moment when they've had to defend democracy, stand up for our personal freedoms, and stand up for our right to vote and our civil rights. This is ours," he said.

In the video, Biden dubbed the 2024 election as a fight against Republican extremism, arguing he needed more time to fully realise his vow to restore the nation's character.

"When I ran for president four years ago, I said we are in a battle for the soul of America. And we still are,” he said in the video, which opened with images of the January 6, 2021, insurrection and abortion rights activists protesting at the US Supreme Court.

"The question we are facing is whether in the years ahead we have more freedom or less freedom. More rights or fewer," he added. "I know what I want the answer to be and I think you do too. This is not a time to be complacent. That's why I'm running for re-election."