President Donald Trump compared his achievements on US race relations to those of Abraham Lincoln in the second and final debate with Joe Biden ahead of the November election.

Mr Trump initially adopted a more restrained tone than he did during their first debate in September, which was quickly derailed by his constant interruptions.

Friday’s clash still featured plenty of personal attacks between two men who evince little respect for each other.

Democrat presidential hopeful Biden renewed his attacks on Mr Trump’s handling of the coronavirus pandemic, while the President levelled unfounded corruption accusations at Mr Biden and his family.

The candidates clashed over healthcare, China policy and – after months of anti-racism protests – race relations, with Mr Biden saying Mr Trump was “one of the most racist presidents” in history.

“He pours fuel on every single racist fire,” Mr Biden said. “This guy has a dog whistle as big as a foghorn.”

Mr Trump responded by criticising Mr Biden’s authorship of a 1994 crime bill that increased incarceration of minority defendants, while asserting he had done more for black Americans than any president with the “possible” exception of Abraham Lincoln in the 1860s.

“Nobody has done more for the black community than Donald Trump, and if you look, with the exception of Abraham Lincoln, the possible exception of Abraham Lincoln, nobody has done what I’ve done,” the President said.

Social media users also expressed amusement when Mr Biden mistakenly called the far-right Proud Boys group, the “poor boys” during the debate.

“He banned Muslims because they are Muslims. … He has made everything worse across the board,” Mr Biden said of the President.

“He said about the poor boys, the last time we were on stage here, he said ‘I tell them to stand down and stand ready’.”

The televised debate from Nashville, Tennessee, represented one of Mr Trump’s last remaining opportunities to reshape a campaign dominated by a pandemic that has killed more than 221,000 people in the United States.

Opinion polls show Mr Trump is trailing Mr Biden, although the contest is tighter in some battleground states likely to decide the election.

“Anyone who’s responsible for that many deaths should not remain president of the United States of America,” Mr Biden said in the debate.

Mr Trump defended his approach to the outbreak and claimed the worst of the pandemic was in the past.

“We’re rounding the corner,” said the President, who has played down the virus for months. “It’s going away.”

Mr Trump also claimed a vaccine was potentially “weeks” away. Most experts say a vaccine is unlikely to be widely available until mid-2021.

Several US states, including the election swing state of Ohio, reported record single-day increases in COVID-19 infections on Thursday, evidence the pandemic is accelerating anew.

The debate was Mr Trump’s final chance to reshape his campaign. Photo: AP

After an opening segment on the pandemic, the second debate pivoted to rapid-fire exchanges over whether either candidate had improper foreign entanglements.

Mr Trump repeated his accusations that Mr Biden and his son Hunter engaged in unethical practices in China and Ukraine. No evidence has been verified to support the allegations and Biden called them false and discredited.

Mr Trump’s effort to uncover dirt on Hunter Biden’s Ukraine business ties led to the President’s impeachment.

Mr Biden defended his family and said unequivocally he had never made “a single penny” from a foreign country before pivoting to accuse Mr Trump of trying to distract Americans.

“There’s a reason why he’s bringing up all this malarkey,” Mr Biden said, looking directly into the camera.

“It’s not about his family and my family. It’s about your family, and your family’s hurting badly.”

Mr Biden also accused the President of skirting his taxes, citing a New York Times investigation that reported Mr Trump’s tax returns show he paid almost no federal income tax over more than 20 years.

“Release your tax returns or stop talking about corruption,” Mr Biden said.

Mr Trump again said he would release his returns only once a longstanding audit was completed, asserting he paid “millions” in taxes. 

After the contentious first debate, Mr Trump passed up another planned debate last week after it was switched to a virtual format following his COVID-19 diagnosis.

On Thursday, the commission that oversees the debate removed plexiglass barriers separating the candidates after Mr Trump provided proof he had tested negative for COVID-19, a source said.

The commission also muted the candidates’ microphones to allow each to deliver two-minute statements on each new topic before turning them back on, in an effort to avoid the chaos of the first debate.

-with agencies