US President Joe Biden has triumphantly declared that the United States is "on the move again" in a rousing speech to Congress, calling for trillions of dollars to rebuild the post-Covid US middle class and give new life to "forgotten" workers.

Lauding the success of mass vaccination against Covid-19, Mr Biden told Congress and the nation on primetime television that "in America, we always get up."

"America is ready for takeoff," he said. "We are working again, dreaming again, discovering again, leading the world again."

Mr Biden, who was celebrating the eve of his 100th day in office, called the vaccine roll-out one of "the greatest logistical achievements" in US history.

However he quickly pivoted to insisting that this national effort must now focus on rebuilding the economy and fighting inequality with "the largest jobs plan since World War II."

In a line that could have come from his Republican predecessor Donald Trump, Mr Biden said working class Americans had been ignored, while the top 1% got richer, and that his plans would give them a chance.

"You feel left behind and forgotten in an economy that's rapidly changing. Let me speak directly to you," Mr Biden said, before going on to promise Americans "good-paying jobs that can't be outsourced."

Biden address: Fist bumps and arm-twisting on Capitol Hill

In every aspect of the primetime speech, Mr Biden echoed his almost daily mantra that "America is back" - both in recovering from the coronavirus disaster and in putting the turbulence of the Trump era behind.

When it comes to foreign policy, he underlined Washington's return to international partnerships damaged under Mr Trump.

"No one nation" can succeed alone, he said, in a rebuke of Mr Trump's isolationist policies.

Among his many references to arch-rival China, Mr Biden said that while Beijing is seeking supremacy, "we welcome the competition" and "are not looking for conflict."

On domestic issues, he made the case for a lengthy Democratic wish list, including police reform, pro-immigrant reforms and gun control - some of the most sensitive issues in US politics.

He pleaded with Republicans and Democrats to work together on one of the nation's most hot button topics, saying "let's end our exhausting war on immigration."

But Republicans showed little sign of listening to Mr Biden's appeals for unity, accusing him of only paying lip service to the idea, while promoting a leftist agenda.

"Our best future won't come from Washington schemes or socialist dreams. It will come from you - the American people," Tim Scott, the Republicans' only Black senator and a rising star, said in an official party rebuttal after Mr Biden finished.

"President Biden promised you a specific type of leadership," he said. "Three months in, the actions of the president and his party are pulling us further and further apart."

US presidents usually bend over backwards to avoid or at least hide tax increases.

However, Mr Biden is banking on popular support for his idea of leaning on the super rich to fund his latest new spending proposal, which he unveiled in the speech - the $1.8 trillion American Families Plan.

The plan, which will need approval by a deeply divided Congress, would pour money into early education, childcare and higher education.

To fund this, the top income tax rate would increase from 37%, where Mr Trump's plan put it, back to its pre-Trump 39.6%.

The Biden plan would also end loopholes and capital income tax breaks, while raising "billions," according to the White House, in a tightened tax regime for inherited wealth.

Americans earning less than $400,000 a year, however, would face no extra taxes.

"My fellow Americans, trickle-down economics has never worked. It's time to grow the economy from the bottom up and middle out," Mr Biden said. "What I've proposed is fair."

The proposed new splurge comes after Congress already approved a $1.9 trillion American Rescue Plan, which injected stimulus into almost every corner of the economy, and is now debating a proposed $2 trillion-plus infrastructure plan.