Joe Biden attacks Donald Trump, warns US democracy at risk in State of Union speech

In what was one of the most important speeches of his long political career, the 81-year-old Democrat aimed to ease concerns about his age, painting himself as the only alternative to an anti-democratic Trump in November's presidential election.

He arrived on the floor of the Capitol to extended cheers from supporters and chants of "four more years."

But in a sign of the multiple challenges facing Biden -- including from the Democratic left -- protesters against his support for Israel's war on Hamas tried to block the motorcade from the White House to Congress.

The annual set-piece presidential speech, which in past years has lasted from around an hour to more than 90 minutes, was a chance for Biden to lay out his campaign platform as the battle to keep Trump from staging a shock comeback begins in  earnest.

Biden was not expected to mention Trump's name, but in excerpts released by the White House earlier, he took a clear dig at the 77-year-old Republican, who has refused to accept his 2020 election defeat and now narrowly leads Biden in the polls.

"My lifetime has taught me to embrace freedom and democracy," Biden said in the excerpts. "Now some other people my age, see a different story: an American story of resentment, revenge, and retribution. That’s not me."

Biden routinely paints Trump -- who was impeached twice as president and faces multiple criminal indictments, including over the January 2021 assault on the Capitol -- as a threat to the survival of US democracy.

- 'Greatest comeback' - 

In his speech, Biden slammed Republican abortion opponents, saying they have "no clue about the power of women in America," in what Democrats see as a key vote-winning issue.

And he touted the booming US economy, even if Americans are still unhappy with high prices and polls show many saying their economic fortunes have not improved.

Biden said that "in thousands of cities and towns the American people are writing the greatest comeback story never told."

The Democrat was also expected to take on the war in Gaza and fury among leftists and the Arab-American community over his strong support for Israel's war against Hamas.

He was to announce during the speech that he has ordered the US military to set up a port on Gaza's coast to bring in more aid, reflecting the acute political pressure from many in his own party.

Ahead of the speech, Trump accused Biden of "horrific devastation" during his three years so far in office, focusing on the record numbers of migrants crossing the Mexican border.

"It's time to tell Crooked Joe Biden -- you're fired," Trump said in a video "prebuttal", using the catchphrase of his former TV reality show "The Apprentice."

- Age concerns -

For the millions of Americans tuning in to the spectacle, much of the interest will be not just what Biden says in the joint session of Congress, but how whether he avoids serious verbal -- or even physical -- stumbles.

Republican rightwingers like Marjorie Taylor Greene were expected to heckle Biden, as they did last year.

In line with tradition, First Lady Jill Biden will host a number of guests chosen to highlight the White House's priorities.

This year they include a Texan woman forced to leave the state for an abortion, a woman whose IVF treatment was halted by an Alabama court ruling, and the prime minister of Sweden, which became NATO newest member on Thursday.