NEW YORK (REUTERS) - US Democratic presidential candidate Joe Biden's first 2020 fund-raiser with former President Barack Obama has netted more than US$4 million (S$5.5 million) from more than 120,000 people ahead of their joint appearance on Tuesday (June 23), the campaign said.

The virtual event could amount to Biden's largest haul from small-dollar donors and comes on the heels of the Democratic Party and his campaign outraising President Donald Trump in May for the first time, US$80.8 million to US$74 million.

The Republican president, who has been campaigning for a second term since 2017, still has a spending advantage ahead of the Nov 3 presidential election.

Trump's campaign, party and other fund-raising entities had US$265 million in cash at the end of May.

The Democrats and Biden, who launched his campaign in April 2019, held a combined US$122 million, not including some fund-raising entities that have not disclosed their records.

Early in the 2020 campaign, Biden's weak fund-raising numbers compared to some of his Democratic competitors were a source of concern. But he has seen his fund-raising from donors pick up in recent weeks as his lead in national opinion polls grew and the country reacted to incidents of police brutality.

The event on Tuesday also shows the drawing power of Obama.

He endorsed Biden, his former vice-president, in April but has not been actively campaigning for Biden as in-person events were largely cancelled due to the coronavirus.

The Biden campaign is hoping to come close to matching Trump's war chest so it can counter his advertising, get-out-the-vote operations in battleground states, and eventual campaign travel with their own.

A high-dollar fund-raising event held last week for Biden with 620 donors and hosted by Senator Elizabeth Warren took in US$6 million, the most ever for Biden's campaign.