Trump, Biden spar over COVID-19, race, climate in final US presidential debate

US President Donald Trump and his challenger Joe Biden clashed over COVID-19, immigration, racism and climate change during their final presidential debate, with both candidates unveiling their sharply divergent visions for the country over the next four years.

The two leaders traded barbs during the debate that lasted just over 90 minutes, attacking each other's positions on controlling the raging coronavirus pandemic and curbing the country's world-leading death toll of over 223,000.

The prime-time debate in Nashville, Tennessee, was a less acrimonious and more substantive affair than their previous showdown on September 29, which devolved into insults and name-calling. This prompted the debate organisers to put in place muted microphones during the candidates' opening statements on each topic to minimise disruption.

The debate ahead of the November 3 presidential election, saw plenty of personal attacks between 74-year-old Trump, a Republican, and his 77-year-old Democratic rival, Biden, whose mutual dislike was quite evident.

Millions of Americans have already made up their minds about the election, with more than 50 million people having cast early ballots by mail or in person due to COVID-19 fears. The figure exceeds the early vote total in 2016. There are about 230 million eligible voters in total.

The coronavirus dominated the opening minutes of the Trump-Biden face-off with President Trump terming the contagion a “worldwide problem”.

"This has been a worldwide problem, but I’ve been congratulated by many countries on what we’ve been able to do,” he said.

Trump once again blamed China for the virus and and said Beijing failed to prevent the disease from becoming a pandemic.

He claimed that America was very close to developing a vaccine against the deadly disease that Biden said was claiming 1,000 lives daily in the US.

"We have a vaccine that's coming, it's ready. It's going to be announced within weeks and it's going to be delivered,” Trump said.

The president said his generals have lined up for the fast distribution of the vaccine, as he expects to have 100 million vials.

Biden challenged Trump and alleged that his policies have resulted in a large number of deaths in the country.

"We are about to go into a dark winter. A dark winter and he has no clear plan and there's no prospect that there's going to be a vaccine available for the majority of the American people before the middle of next year,” he said.

Trump, who has often said the worst is over with the pandemic, reasserted this, claiming the US was “rounding the turn" and the country is learning to live with it.

"He always says people are learning to live with it. People are learning to die with it. I will take care of this. I will make sure we have a plan,” Biden responded.

On climate change, Trump accused China, India and Russia of not taking care of their “filthy air” as he justified America's withdrawal from the landmark Paris climate agreement.

"Look at China, how filthy it is. Look at Russia. Look at India, it's filthy. The air is filthy. We have the best emission numbers that we've had in 35 years under this administration. We are working so well with the industry," he said.

"The Paris Accord, I took us out because we were going to have to spend trillions of dollars and we were treated very unfairly. When they put us in there, they did is a great disservice. They were going to take away our businesses," he asserted.

"We have the best environmental numbers, ozone numbers, and so many other numbers. In the meantime, China, Russia, India all these countries they're spewing stuff into the air,” he alleged.

Biden and Trump clashed on race relations, a topic that has gained prominence after the horrific murder of an African American in police custody early this year in Minneapolis.

Biden termed Trump "one of the most racist presidents we've had in modern history", asserting that his Republican rival at his last debate did not condemn white supremacy and told an extremist group to "stand down and stand by.” "Here is one of the most racist presidents we've had in modern history. He pours fuel on every single racist fire. Every single one," Biden alleged.

The US president portrayed himself as a champion of Black people and reiterated that no president has done more for Black Americans than anyone other than former US President Abraham Lincoln.

"Nobody has done more for the black community than Donald Trump. And if you look, with the exception of Abraham Lincoln, possible exception, with the exception of Abraham Lincoln, nobody has done what I've done,” Trump claimed.

Trump said that he didn't "know what to say" in response to Americans who say that his words have fanned the flames of racial division.

"I think I have great relationships with all people. I am the least racist person in this room," Trump claimed.

When the debate moved to the topic of immigration, Trump appeared callous about the toll that his policies have taken on over 500 children who were separated from their parents at the border.

"They are so well taken care of. They are in facilities that are so clean," Trump said.

Trump's cold response allowed Biden to attack the president, calling his family separation policy contrary to everything that America stands for.

The two candidates accused each other of serious corruption charges.

Trump attacked Biden, saying, "I don't make money from China. You do. I don't make money from Ukraine. You do. I don't make money from Russia. You made USD 3.5 million".

"My son has not made money in terms of this thing about what are you talking about, China. The only guy that made money from China is this guy (Trump). He's the only one. Nobody else has made money from China," Biden said.

Trump asserted that success is going to bring America together, while Biden said that the character of the country was on the ballot in the election.

While both candidates scored important points in their final debate, neither appeared to have secured the upper hand that might alter the course of the campaign, analysts said.

In snap polls - from CNN, Data Progress and US Politics - most respondents said Biden won the debate by a margin of more than 50 per cent to about 40 per cent.

Biden has established a solid national lead with 12 days to go until the election. But the margin is slimmer in the handful of states that could vote either way and ultimately decide the outcome on November 3.