Joe Biden was heckled and called a “liar” as Republicans booed during rowdy scenes at his annual State of the Union address.
It came as the US president had said he would seek “unity” during the speech in order to “finish the job”.
But the atmosphere turned sour when he accused Republicans of wanting to cut benefits for the elderly.
Dozens of Republican senators and members of Congress rose to their feet and booed loudly, some making thumbs-down gestures.
Marjorie Taylor Greene, the Republican congresswoman and friend of Donald Trump, yelled “Liar!” at Mr Biden.
Mr Biden had said that “some of my Republican friends want to take the economy hostage unless I agree with their economic plans,” which he said included cuts to Social Security and Medicare.
Amid the booing Mr Biden abandoned his prepared speech, instead saying: “Anybody who doubts it, contact my office.”
He appeared to have been referring to a proposal from one Republican senator, which has already been dismissed by the majority of the Republican party.
As the jeering subsided Mr Biden said: “Well I’m glad. I’ll tell you I enjoy conversion. So, we all agree, apparently, let’s stand up for seniors.”
Mr Biden was also heckled when he spoke about the fentanyl epidemic. Several Republicans shouted: “It’s your fault.”
A warning to China
Mr Biden issued a warning to Beijing after a Chinese spy balloon traversed the continental United States before eventually being shot down by the US military last week.
He said: “Make no mistake about it, as we made clear last week, if China threatens our sovereignty, we will act to protect our country.
“Before I came to office, the story was about how the People’s Republic of China was increasing its power and America was falling in the world. Not anymore.”
He said the US would invest in “industries that will define the future, and that China’s government is intent on dominating” and “protect our advanced technologies so they’re not used against us.”
The US would modernise its military to “safeguard stability and deter aggression”. He added: “Let’s be clear, winning the competition with China should unite all of us.
“In the past two years democracies have become stronger, not weaker. Autocracies have grown weaker, not stronger.”
Shouting, he said: “Name me one world leader who would swap places with Xi Jinping, Name me one.
“Those who bet against America are learning just how wrong they are.”
Democrats chanted “USA, USA!” Ms Greene heckled: “China is spying on us!”
US will stand with Ukraine ‘as long as it takes’
Mr Biden directly addressed Oksana Markarova, the Ukrainian ambassador to the US, who was sitting with First Lady Jill Biden and U2 singer Bono.
He said: “She represents not just her nation, but the courage of her people.
“Ambassador, America is united in our support for your country. We will stand with you as long as it takes.”
Mr Biden gave few specifics on what would be next in terms of weapons for Ukraine.
But he said: “Putin’s invasion has been a test for the ages. A test for America. A test for the world.
“One year later, we know the answer. Together, we did what America always does at our best. We led. We united Nato and built a global coalition. We stood with the Ukrainian people.”
Tax the rich
Mr Biden set out what will be a plank of his re-election effort in 2024, vowing to increase taxes on the wealthy.
He said: “Reward work, not just wealth, because no billionaire should pay a lower tax rate than a school teacher or a firefighter.”
The president called on Congress to pass his proposed minimum tax on billionaires, receiving loud cheers from Democrats.
According to the White House US billionaires currently pay, on average, eight per cent in tax. Mr Biden has previously advocated that they should pay at least 20 per cent.
He also called for the quadrupling of the one per cent tax on corporate share buybacks. The one per cent tax was introduced as part of his Inflation Reduction Act last year.
Such moves have little chance of becoming law in a bitterly-divided Congress. Mr Biden also called the profits being made by oil companies “outrageous”.
He accused technology companies of running a for-profit “experiment” on children, and attacked big pharmaceutical companies for charging too much for insulin.
‘Finish the job’
Mr Biden used the phrase “finish the job” at least a dozen times during his 73-minute address. It sounded like a test-run for a slogan he may use in the 2024 campaign.
He suggested that rebuilding the economy after the pandemic and uniting the country were a work in progress he needed more time for.
With a divided congress it is improbable that he will be able to “finish the job” on various issues he mentioned, such as securing a ban on assault weapons.
The speech was Mr Biden’s biggest chance of the year to reach a TV audience – 38 million watched last year – and he wanted to show that he is ready to run again in his 80s.
However, only 37 per cent of Democrats say they want him to seek a second term, down from 52 per cent before the midterm elections in November, according to an Associated Press-NORC poll.
A Washington Post-ABC News poll showed 62 per cent of Americans believe he has done “not very much” or “little or nothing” since taking office.
Republicans accuse Biden of ‘lighting money on fire’
The official Republican response to the State of the Union was delivered by Sarah Huckabee Sanders, the new governor of Arkansas, and former press secretary to Donald Trump.
She accused Mr Biden of reckless spending, stoking culture wars, and promoting “woke fantasies”.
Mrs Sanders said: “In the radical left’s America, Washington taxes you and lights your hard-earned money on fire, but you get crushed with high gas prices, empty grocery shelves, and our children are taught to hate one another on account of their race.”
She said Mr Biden was “unfit to serve as commander in chief” and that his “weakness puts our nation and the world at risk.”
Mrs Sanders, 40, is the youngest state governor in the US and exactly half Mr Biden’s age. She added: “It’s time for a new generation of Republican leadership.”