President Donald Trump made a pitch for national unity and strong borders in his maiden State of the Union address on Tuesday, calling for "one team, one people, and one American family" after a year plagued by acrimony, division and scandal.

He also announced that he would keep Guantanamo Bay open, breaking from his predecessor Barack Obama's lengthy and ultimately failed efforts to shutter the maligned detention facility.

"I just signed an order directing Secretary Mattis to reexamine our military detention policy and to keep open the detention facilities at Guantanamo Bay," Trump said, in his address to Congress, in keeping with a campaign promise.

On the campaign trail, Trump had famously vowed he would load Guantanamo with "bad dudes" and said it would be "fine" if US terror suspects were sent there for trial.

Read: Guantanamo Bay, the infamous jail Obama could not shut

Though Obama could not closed Guantanamo, the population had dropped from 242 to 41 under his watch.

During his speech, the president also said that he wanted Congress to pass a law ensuring US foreign aid goes only “to America’s friends” — a reference likely to his frustration at US aid recipients that voted at the UN to rebuke his decision to recognise Jerusalem as Israel’s capital.

'One American family'

Delivering his biggest speech of the year, this most polarizing of presidents sought to put the spotlight on the economic achievements of his first year in office and called on a packed joint session of Congress to enact hardline 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 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.

Looking on, were dozens of Democratic lawmakers, some decked in black to honour 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.

Also in the audience were members of Trump's own family including the first lady, Melania, who recently cancelled a joint trip to Davos, Switzerland and has not been seen with her husband in public since reports alleged he paid porn actress Stormy Daniels hush money over an affair, which the White House denies.

Breaking with tradition, the first couple arrived separately to the Capitol, because, according to the first lady's spokesperson Stephanie Grisham, she was accompanying guests.

Curbs on immigration

Over the years the State of the Union address, a set piece of the American political calendar, has lost some of its impact and pizzazz.

But the primetime address, watched by as many as 40 million Americans, was still a once-in-a-year opportunity for Trump to speak to the nation and mend his sunken approval ratings, languishing around 40 percent.

Seeking to enliven his own base, Trump spoke at length on the need for immigration reform, equating immigrants with criminals and economic tension.

For decades, he lamented, "open borders" had allowed "drugs and gangs to pour into" the United States. He again called for the construction of a border wall that remains unfunded in Congress.

"They have allowed millions of low-wage workers to compete for jobs and wages against the poorest Americans. Most tragically, they have caused the loss of many innocent lives."

Two couples whose daughters were murdered by MS-13, a Salvadoran gang, were among those joining the First Lady to watch the address.

"The United States is a compassionate nation" he said, "but as president of the United States, my highest loyalty, my greatest compassion, and my constant concern is for America's children, America's struggling workers, and America's forgotten communities."

Wall Street Don

The 71-year-old real estate mogul and reality TV star touted a long bull run on Wall Street and improving growth rates, something the White House has dubbed a "Trump bump."

"The stock market has smashed one record after another, gaining $8 trillion in value," he said, even though that narrative suffered a setback when stocks suffered their biggest drop in eight months on Tuesday amid fears of a bubble.

"Since the election, we have created 2.4m new jobs, including 200,000 new jobs in manufacturing alone. After years of wage stagnation, we are finally seeing rising wages."

"Just as I promised the American People from this podium 11 months ago, we enacted the biggest tax cuts and reform in American history," Trump said.

Trump also lifted his gaze beyond the United States, calling for "fair" trade and declaring that "the era of economic surrender is over."

US security

He also focused on what Washington sees as Iran's troublesome activities across the Middle East, as well as North Korea's nuclear and ballistic missile programs.

"America stands with the people of Iran in their courageous struggle for freedom," he said, while warning that "North Korea's reckless pursuit of nuclear missiles could very soon threaten our homeland."

In a nod to his recent National Security Strategy which eyed geopolitical adversaries as a greater threat than terrorism, he also said that China and Russia "challenge our interests, our economy, and our values".

Still there was a focus on terror, which had been a central message of his campaign.

He said America and her allies have liberated "almost 100 per cent of the territory" once held by the militant Islamic State (IS) group, admitting "there is much more work to be done."

Trump said he was also asking Congress to ensure the US had needed powers to detain IS group members and other “terrorists wherever we chase them down”, though it was unclear whether he was referring to a new war powers authorisation or some other mechanism.