US President Joe Biden urged Americans to “stand guard” against a “dangerous” oligarchy forming under Donald Trump as he delivered a dark farewell address before stepping down next week.

In a primetime speech from the Oval Office at the end of his single term in office, the 82 year old warned of an ultra-wealthy “tech industrial complex” that could gain unchecked power over the American people.

“Today, an oligarchy is taking shape in America of extreme wealth, power and influence that literally threatens our entire democracy,” the 82-year-old Democrat said.

“That’s a dangerous concentration of power in the hands of a very few ultra-wealthy people.”

Biden also lashed out at social media firms, with X owner and the world’s richest man Elon Musk set to play a key role in Trump’s incoming administration and Meta boss Mark Zuckerberg courting the Republican.

“Americans are being buried under an avalanche of misinformation and disinformation, enabling the abuse of power,” said Biden.

Biden also warned of the dangers of AI, saying that America must take the “lead” over China on the transformative technology, and said that “powerful forces” threatened his climate achievements.

Signing off Trump returns for a second term on January 20, Biden told Americans: “Now it’s your turn to stand guard.”

Biden’s speech took a dark turn after he began by touting his legacy on the economy, healthcare, climate and tackling the gun violence that plagues the United States.

America’s oldest ever President has spent much of his final months in office trying to burnish his reputation before he is replaced by the bitter political rival he defeated in the 2020 election – a result Trump still disputes.

Biden’s efforts got a boost when Israel and Hamas agreed to a ceasefire and hostage release deal Biden said he’d ordered his administration to cooperate with Trump’s team to reach an accord.

‘Soul of America’

But his legacy was badly damaged by his decision to run for a second term despite his age.

The Democrat was forced to drop out of the race last June after a disastrous debate against Trump, 78, who went on to a commanding victory over Biden’s vice president, Kamala Harris.

Polls show Biden remains an unpopular president. A CNN poll showed him with a 36% approval rating, remaining at the lowest of his term.

That puts him above Trump, who left office with a 34% approval rating, according to the American Presidency Project. The lowest in recent times was Richard Nixon with 24% while the highest was Bill Clinton with 66%, followed by Barack Obama with 59%.

In a letter previewing his remarks, Biden took an implicit swipe at Trump, saying that he “ran for President because I believed that the soul of America was at stake”.

“And, that’s still the case,” Biden said in the letter.

Biden added in the letter that “I have given my heart and my soul to our nation” and that it had been the “privilege of my life to serve this nation for over 50 years”.

The White House also released a dossier of more than 100 pages setting out his achievements from the economy to healthcare and climate change.

In a farewell interview in the Washington Post published Wednesday, outgoing First Lady Jill Biden took a dig at the Democratic Party for pressing Biden to drop out.

“Let’s just say I was disappointed with how it unfolded,” she said.

Emotions ran high at the White House ahead of his speech.

Press secretary Karine Jean-Pierre – part of a team that brought back regular media briefings after Trump ended them during his first term – fought back tears on her last appearance at the famous podium as she described the “honour of a lifetime”.

–Agence France-Presse