State of the Union: President Donald Trump calls for unity after longest ever government shutdown

Facing a divided Congress for the first time, President Donald Trump has called on Washington to govern "not as two parties, but as one nation" - a message that clashed with the rancorous atmosphere in the nation's capital after the longest government shutdown in history.

Trump, who has spent two years levelling fiercely personal attacks on his Democratic rivals, declared that it was time "to bridge old divisions, heal old wounds, build new coalitions, forge new solutions and unlock the extraordinary promise of America's future."

Trump's speech to lawmakers and the nation comes at a critical moment in his presidency. He pushed his party into a lengthy government shutdown over border security, only to cave to Democrats.

With another shutdown deadline looming, the president has few options for getting Congress to fund a border wall, and he risks further alienating his party if he tries to circumvent lawmakers by declaring a national emergency instead.

As he stood before lawmakers, the president was surrounded by symbols of his emboldened political opposition. House Speaker Nancy Pelosi, who was praised by Democrats for her hard-line negotiating during the shutdown, sat behind Trump as he spoke.

House Democratic women created a sea of white, donning the colour favoured by early 20th-century suffragettes. And several senators running for president were also in the audience, including Senators. Kamala Harris of California and Cory Booker of New Jersey.

Another Democratic star, Stacey Abrams, will deliver the party's response to Trump. Abrams narrowly lost her bid in November to become America's first black female governor, and party leaders are aggressively recruiting her to run for US Senate from Georgia.

In excerpts released ahead of Abrams' remarks, she calls the shutdown a political stunt that "defied every tenet of fairness and abandoned not just our people, but our values."

Speaker Nancy Pelosi and dozens of other women Democrats are wearing white to President Donald Trump's State of the Union address.

As Pelosi climbed the dais, they gathered in the aisle of the Democratic side of the House, raising their voices and hands as other members raised their cell phones and recorded the moment. Most women on that side of the House chamber were wearing the colour favoured by suffragettes and the president's opponents who want him to see them from the dais.

Alexandria Ocasio-Cortez wore a white caped blazer. A man wore white, too: Dean Phillips of Minnesota.

The palpable excitement comes after the November elections sent a record number of women, most of them Democrats, to Congress.