The Democratic Party could adopt rules Tuesday allowing delegates to vote remotely due to the COVID-19 pandemic to nominate Joe Biden for 2020 US presidential race, a party official said.

Former vice president Biden is the sole contender on the Democratic side to face Republican Donald Trump in the November 3 presidential vote, but he has yet to formally be nominated.

Biden's last remaining party rival, Bernie Sanders, endorsed him for president in mid-April, saying it was time to unite to defeat Trump.

Now a resolution will be submitted to grant the convention committee "maximum flexibility to plan a safe event that guarantees every delegate can accomplish their official business without putting their own health at risk," a party official told AFP.

"During this critical time, when the scope and scale of the pandemic and its impact in August remain unknown, convention planners are exploring a range of contingency options to ensure all delegates will be able to cast ballots and accomplish their business, regardless of their ability to travel and participate in person," the official said.

The resolution will ratify the change of dates, and also give its organizers the possibility of further modifying the calendar, as well as its format and the size of the event, the party official said.

The proposal would need to be approved by some 450 members of the party leadership, who may be able to vote by mail.

Thousands of people gather every four years for the Republican and Democratic Party conventions in which the presidential candidates are officially nominated.

The Republican Party convention is scheduled for August 24-27 in Charlotte, North Carolina. No changes have yet to be announced.

The virus lockdown has slammed the US economy and upended political campaigning this season.

More than 80,000 people have died in the pandemic in the United States as of late Monday.AFP