US President Donald Trump is delivering his annual State of the Union address before Congress.
The Republican president called for political unity, hours after using an offensive term to describe the Democratic leader of the US Senate.
He will also use the speech to address border security, and talk about North Korea and the trade dispute between the US and China.
In a rebuttal, Democrats will accuse Mr Trump of abandoning US values.
Mr Trump’s primetime address follows the longest US government in history over border security.
He provoked the crippling closure of federal agencies by demanding funding for a US-Mexico border wall only to backtrack when Democrats flatly refused.
After two years of toxic partisanship, Mr Trump on Tuesday night repeated calls for political unity that he has made in his previous two State of the Union speeches.
“Together, we can break decades of political stalemate,” he said.
“We can bridge old divisions, heal old wounds, build new coalitions, forge new solutions, and unlock the extraordinary promise of America’s future. The decision is ours to make.”
Mr Trump offered an olive branch to opponents, targeting potential areas of agreement, such as infrastructure improvements, lowering prescription drug costs and healthcare.
But in an apparent reference to Democratic accusations that his campaign colluded with Russia during the 2016 election campaign, he criticised “ridiculous partisan investigations”.
Hours before the speech, Chuck Schumer, the Democratic leader of the Senate, poured pre-emptive scorn on Mr Trump’s remarks.
The New York senator said on the chamber floor: “It seems every year the president wakes up and discovers the desire for unity on the morning of the State of the Union, then the president spends the other 364 days of the year dividing us, and sowing a state of disunion.”
The president fired back on Twitter: “I see Schumer is already criticising my State of the Union speech, even though he hasn’t seen it yet.”
In a private lunch with news anchors at the White House on Tuesday, Mr Trump called Mr Schumer “nasty”, using an offensive term, reports the New York Times.
The president was also quoted as having called former US Vice-President Joe Biden, a potential White House challenger in 2020, “dumb”.
As Mr Trump delivered his primetime speech on Tuesday, his chief congressional antagonist was sitting at the rostrum over his shoulder.
The Democratic leader of the House of Representatives, Speaker Nancy Pelosi, led congressional resistance to the president’s demands for wall funding and regularly mocks him.
Stacey Abrams, who lost her race last year to be governor of Georgia, will deliver the Democrats’ response to Trump, making her the first African-American woman to deliver the party’s rebuttal.
She was expected to say: “The shutdown was a stunt engineered by the president of the United States, one that defied every tenet of fairness and abandoned not just our people – but our values.”
A number of Democratic female lawmakers were wearing white, the colour favoured by early 20th Century suffragettes.
For most of the speech, they sat stony-faced as their Republican counterparts got to their feet for the applause lines.
But in a rare outbreak of bipartisanship, Mr Trump received a standing ovation from Democratic female lawmakers when he said there were more women in the workforce and in Congress than ever before.
“That’s great!” said the president. “Really great.”
The president vowed again to build wall on the border, pointing out that many lawmakers had previously supported such a barrier.
But with another government shutdown deadline looming next week, the president has few options for getting Congress to fund a border wall.
He did not declare a national emergency instead on Tuesday night, in an attempt to get around lawmakers and fulfill his signature campaign promise.
Mr Trump told his audience that working class Americans pay the price for illegal immigration.
He pointed to a guests in the audience, a woman whose parents he said had been killed in Nevada by “an illegal alien”.
“Not one more American life should be lost because our nation failed to control its very dangerous border,” said Mr Trump.
