In a primetime address, the Republican leader said he is “extending an open hand” to Democrats to work together.
Mr. Trump also said he was ordering Guantanamo Bay to be kept open, reversing an Obama-era directive to close the controversial detention camp.
The American economy is booming but Mr. Trump’s approval rating languishes.
In an upbeat message a world away from his apocalyptic “American carnage” inaugural speech of just a year ago, Mr. Trump said his administration is “building a safe, strong and proud America”.
“There has never been a better time to start living the American dream,” he told lawmakers.
As many as 40 million television viewers were expected to tune in as he implored the nation to come together as “one team, one people and one American family”.
Mr. Trump made a plea for the kind of bipartisan co-operation that has been in short supply during a turbulent first year in office.
The president, who has enraged Democrats by withdrawing protections for immigrants who entered the US illegally as children, offered an olive branch.
“Tonight I am extending an open hand to work with members of both parties, Democrats and Republicans, to protect our citizens, of every background, colour and creed.”
Mr. Trump again touted his pet plan to rebuild America’s aging roads and other infrastructure, though he did not offer many details.
The president said 2.4 million jobs had been created on his watch.
Since he came to office, the stock market has soared and the unemployment rate is at a 17-year low as the US continues its recovery from the Great Recession of a decade ago.
But Mr. Trump has often complained that he does not get enough credit for the rosy outlook.
He had an average job approval last year of 38%, the lowest first-year rating for any president in the history of Gallup polling.
He attempted to seize Mr. Trump’s political mantle by purporting to speak for “Americans who feel forgotten and forsaken”.
Bewailing a “fractured country” and depicting the Trump presidency as “chaos”, Mr. Kennedy, 37, said: “Many have spent the past year anxious, angry, afraid.”
“Bullies may land a punch,” he said. “They might leave a mark.
“But they have never, not once, in the history of our United States, managed to match the strength and spirit of a people united in defence of their future.”
In one telling moment from Mr Trump’s speech, members of the Democratic Congressional Black Caucus sat in stony-faced silence amid a standing ovation as the president noted African-American unemployment has hit a record low.
About a dozen Democratic lawmakers said they would boycott Mr Trump’s speech.
Mr. Trump condemned “depraved” North Korea.
He warned that Pyongyang’s “reckless pursuit of nuclear missiles could very soon threaten our homeland.
“We are waging a campaign of maximum pressure to prevent that from happening.”
Mr. Trump paid tribute to a disabled defector from the regime, Ji Seong-ho, who fled the country on crutches and was in the audience.
The president also noted that nearly all the territory in Syria and Iraq once controlled by the Islamic State group has been retaken.
“We will continue our fight until ISIS is defeated,” Mr Trump vowed.
While his two White House predecessors have used their State of the Union speeches to forecast victory for American forces in Afghanistan, Mr. Trump largely skirted what is now America’s longest war.
In an apparent acknowledgment of the deteriorating security situation there, he said the US “military is no longer undermined by artificial timelines”.
He only mentioned Russia once alongside China as a rival.
SOURCE: BBC News