Declaring that "America is rising anew" under his leadership, President Joe Biden has told China that the US will maintain a "strong" military presence in the Indo-Pacific "not to start conflict, but to prevent one" as Beijing became more assertive in the strategically vital region.

Using his maiden address to the joint session of Congress on the eve of his 100th day in office to make a strong case for huge new investments and tax reforms to overhaul the US economy and rebuild the middle class, Biden said, "we have acted to restore the people's faith in our democracy to deliver."

In a historic moment, Vice President Kamala Harris - the first woman to hold the second highest office - and House Speaker Nancy Pelosi both sat behind Biden during Wednesday night's prime time address. It was the first time two women appeared behind the president during a speech to Congress.

After addressing Harris in his opening remarks as Madam Vice-President, Biden added: "No president has ever said those words from this podium. And it's about time."

In his 65-minute address, Biden spent the majority of his time to discuss his economic and infrastructure plans for the nation, his foreign policy vision for America's role in the world and the coronavirus pandemic and other health care issues.

"Life can knock us down. But in America, we never stay down. In America, we always get up. And today, that's what we're doing: America is rising anew," he said.

"After 100 Days of rescue and renewal, America is ready for takeoff. We are working again. Dreaming again. Discovering again. Leading the world again. We have shown each other and the world: There is no quit in America," he said.

Biden then went on to describe a two-hour conversation he had with Chinese President Xi Jinping upon taking office in January.

"I told President Xi that we will maintain a strong military presence in the Indo-Pacific just as we do with NATO in Europe, not to start conflict, but to prevent conflict," he said.

China claims sovereignty over all of the South China Sea. Vietnam, Malaysia, the Philippines, Brunei and Taiwan have counter claims.

China is engaged in hotly contested territorial disputes in both the South China Sea and the East China Sea. Beijing has built up and militarised many of the islands and reefs it controls in the region. Both areas are stated to be rich in minerals, oil and other natural resources and are also vital to global trade.

Biden said that he also told Xi that "we welcome the competition - and that we are not looking for conflict."

"But I made absolutely clear that I will defend American interests across the board," he added.

He said America will stand up to "unfair" trade practices that undercut American workers and industries, like subsidies for state-owned enterprises and the theft of American technologies and intellectual property.

"He's (President Xi) deadly earnest on becoming the most significant, consequential nation in the world. He and others, autocrats, think that democracy can't compete in the 21st century with autocracies. It takes too long to get consensus," he said.

Biden also said that he told Xi what he has said to many world leaders - that America won't back away from its commitment to human rights and fundamental freedoms.

"No responsible American president can remain silent when basic human rights are violated. A president has to represent the essence of our country," he added.

Biden offered stern words for his Russian counterpart Vladimir Putin, saying he made it very clear to him that while the US doesn't seek escalation, their actions have consequences.

"I responded in a direct and proportionate way to Russia's interference in our elections and cyber attacks on our government and businesses - and they did both of those things and I did respond," Biden said.

"But we can also cooperate when it's in our mutual interests," he said.

Biden also said that the climate crisis is not America's fight alone, but a global one as he asserted that he pushed for the US to meet its international obligations to slow the impact of climate change.

He said that the US accounts for less than 15 per cent of carbon emissions while the rest of the world accounts for 85 per cent. "That's why - I kept my commitment to rejoin the Paris Climate Agreement on my first day in office," he said.

While former president Barack Obama signed the Paris Climate Accord his successor Donald Trump pulled the US out, calling it unfair to American coal miners and the energy industry. Biden has rejoined the landmark accord soon after assuming office.

"I kept my commitment to convene a climate summit in America of all the major economies in the world, China, Russia, India, European Union. I started doing it in my first 100 days," Biden said.

"I wanted the world to see that there is consensus that we are at an inflection point in history. And the consensus is if we act, we can save the planet - and we can create millions of jobs and economic growth and opportunity to raise the standard of living for everyone in the world," he added.

Assuring fellow citizens that his administration will maintain capabilities to suppress future threats to the homeland, Biden said that after 20 years of American valour and sacrifice in Afghanistan, it's time to bring troops home.

"But make no mistake - the terrorist threat has evolved beyond Afghanistan since 2001 and we will remain vigilant against threats to the United States, wherever they come from," he said.

Biden also touted the success of his administration's COVID-19 vaccine rollout and urged everyone to get vaccinated against the deadly disease that has claimed over 574,000 lives in the country.

He quoted the IMF as saying that the US economy will grow at the rate of more than 6 per cent this year. "That will be the fastest pace of economic growth in this country in four decades," he said.

He proposed a USD 1.8 trillion investment in children, families and education to help rebuild an economy devastated by the virus and compete with rising global competitors.