Biden and Trump return to campaign trail after duelling town halls

President Donald Trump and Democratic challenger Joe Biden will return to the campaign trail on Friday, a day after the two contenders clashed from afar during duelling televised town halls.

The split-screen events, which replaced a presidential debate that was cancelled in the wake of Trump's coronavirus diagnosis, also highlighted the sharp contrast between the two candidates' approach to the campaign less than three weeks before the November 3 election.

A combative Trump, sparring with moderator Samantha Guthrie on NBC, refused to condemn the bizarre conspiracy theory QAnon, claimed the 2020 election is rife with fraud and questioned whether masks can help combat the spread of COVID-19. Biden delivered policy-heavy answers and focused his attacks on Trump's handling of the pandemic, which has killed 216,000 Americans and hammered the economy.

Biden has led the contest for months, according to polls, and it was not clear whether Trump's aggressive posture would succeed in altering what has been a stable race despite a whirlwind of news.

More than 18 million Americans have already cast ballots, far more than at a similar juncture in 2016, according to a tracker at the US Elections Project at the University of Florida.

Louisiana will begin early voting on Friday, following record turnout in competitive states Georgia, Texas and North Carolina this week.

Trump will travel to Florida and Georgia, two states that are seen as crucial to his chances of victory, while Biden will visit two cities in Michigan, another battleground state.

The second presidential debate had been scheduled for Thursday, but Trump pulled out of the event after organisers said it would be virtual to lessen the risk of infection.

Trump, who received treatment for several days at a military hospital after he contracted the virus two weeks ago, has since returned to headlining massive campaign rallies.

During his town hall on NBC in front of voters in Miami, Trump declined to say when he last tested negative for the virus before announcing his diagnosis, a question that White House physicians have also refused to answer.

The third presidential debate is scheduled for October 22.