Democratic presidential nominee Joe Biden's campaign strove on Sunday to keep its focus on the nation's response to the coronavirus pandemic, as President Donald Trump received treatment for COVID-19 at a military hospital.

Biden, who shared a debate stage with Trump last Tuesday, tested negative for the coronavirus again on Sunday, following two negative tests on Friday, the day Trump disclosed his COVID-19 infection.,

Biden and his wife, Jill, are due to resume in-person campaigning on Monday in Florida, where opinion polls show a tight race for the state's crucial 29 electoral college votes less than a month before the Nov. 3 election.