US President Donald Trump and Democratic vice presidential candidate Joe Biden squared off in duelling town hall-style meetings broadcast simultaneously on Thursday.
Mr Trump backed out of a debate originally scheduled for Thursday after organisers moved the event online as a precaution after his Covid-19 diagnosis.
With less than 20 days until the election, the unusual format prevented voters from comparing the candidates and their policies side by side.
The presidential rivals took questions in different cities on different networks: Mr Trump on NBC from Miami; and Mr Biden on ABC from Philadelphia.
With Mr Trump returning to the campaign trail following his hospitalisation for Covid-19, Mr Biden is looking to sit tight and maintain his considerable lead in polling numbers.
The Democratic candidate opened the night with a scathing critique of the president’s handling of the coronavirus pandemic.
“He didn’t tell anyone because he was afraid Americans would panic,” said Mr Biden, alluding to an interview the President gave in February that showed he knew how dangerous the virus was.
“Americans don’t panic. He panicked," said Mr Biden.
"It is a presidential responsibility to lead and he didn’t do that."
Mr Biden said he had many suggestions on how to better handle the national health crisis.
With many schools across the US now open, the former vice president called for more teachers and smaller pods of pupils.
He said ventilation systems need to be changed after growing evidence from research that the virus can be airborne.
Mr Biden also slammed the Trump administration for failing to administer an effective testing and tracing programme, saying it was a “critical piece” of pandemic control.
He condemned the president for spreading misinformation, pointing to an earlier statement from Mr Trump suggesting Americans could inoculate themselves by injecting bleach.
“Crazy stuff,” Mr Biden said. “The words of a president matter.
“When a president doesn’t wear a mask or makes fun of people like me for wearing a mask for a long time, then people say, 'well, it mustn't be that important'."
Mr Trump has come under fire for spreading Covid-19 misinformation on social media, prompting platforms including Twitter and Facebook to delete posts from the president that contained false information about the coronavirus.
Mr Biden added that he would take a vaccine if it were approved and went through the proper scientific channels.
"Yes. I'd take it and encourage people to take it."
On the topic of foreign policy, the former vice president said the Trump administration has made America “more isolated in the world than we’ve ever been.”
He said America’s NATO allies can’t count on the US anymore, as Mr Trump “embraces all the thugs of the world.”
“He’s best friends with the leader of North Korea, sending love letters, he doesn’t take on Putin in any way,” said Mr Biden.
“America first has made American alone."
He also warned that since Mr Trump pulled out of the Iran nuclear deal, negotiated by the Obama administration, Iran is "closer to having enough nuclear material to build a bomb."
With weeks to go until the November 3 vote, the Supreme Court has become a hotly contested election issue as Republicans rush to confirm nominee Amy Coney Barrett to fill the empty lifetime appointment on the court.
Fearing the court will lean to the Republicans, some Democrats have suggested "packing the court" with additional judges to counter the Republicans on the bench.
Mr Biden has refused to offer a position on the matter, calling it a distraction, but when pressed by ABC's George Stephanopoulos, the Democratic candidate said he would provide a firm answer before the election.
"I have not been a fan of court packing," said Mr Biden, but refused to rule it out.
He said his position would depend on how Republicans handled Judge Amy Coney Barrett’s nomination.
After the official town hall ended, Mr Biden stayed on stage for over 30 minutes to field questions from audience members.
Earlier in the day, Democratic vice presidential candidate Kamala Harris announced she would suspend all campaign travel until October 18 after two people on a flight with her tested positive for Covid-19.
“Senator Harris has taken two tests since then and the tests have been negative," the campaign office said.
It was also announced that a passenger on Joe Biden’s campaign plane tested positive for Covid-19. The passenger worked for the aviation charter company used by Mr Biden.