WASHINGTON: President Donald Trump appealed Tuesday for national unity and strong borders in his first State of the Union address, calling for "one American family" after a year marred by acrimony, division and scandal.

Delivering his biggest speech of the year, this most polarizing of presidents sought to put the spotlight on a robust economy, while pointedly calling on a packed joint session of Congress to enact tough curbs on immigration.

"Tonight, I call upon all of us to set aside our differences, to seek out common ground, and to summon the unity we need to deliver for the people we were elected to serve," he said. "Tonight, I want to talk about what kind of future we are going to have, and what kind of nation we are going to be. All of us, together, as one team, one people, and one American family."

Trump's opening tone was uncharacteristically conciliatory, although it bridged no compromise on his drive to reduce immigration -- which he painted as responsible for a plethora of social ills.

He touched on a range of foreign policy issues -- including, in an emotive moment, offering the spotlight to crippled North Korean amputee defector Ji Seong-ho, who waved a crutch in the air as he received a prolonged standing ovation.

Trump warned that Pyongyang's "reckless" nuclear drive could "very soon" threaten the US homeland, while also eyeing the geopolitical challenge posed by adversaries China and Russia.

But Trump's State of the Union, the third longest on record at one hour 20 minutes, was overwhelmingly focused on domestic concerns.

Among those looking on were dozens of cross-armed Democratic lawmakers, some decked in black to honor the victims of sexual harassment and still others wearing butterfly stickers in support of immigrants -- two social issues that more than any others have roiled America in the age of Trump.