Washington, Oct 28 (IANS): Despite falling behind on fundraising, former US Vice President Joe Biden has expressed confidence in his presidential campaign for the 2020 election.

"I know I'm the frontrunner," Xinhua news agency quoted the Democratic presidential contender as saying in an interview with CBS News on Sunday night.

"We're on a course to do extremely well. I'm not worried about being able to fund this campaign."

Biden raised $15.2 million in the third quarter of this year, his campaign had announced earlier this month.

In comparison, his fellow top-tier 2020 Democratic candidates, Senators Bernie Sanders of Vermont and Elizabeth Warren of Massachusetts, took in $25.3 million and $24.7 million, respectively.

Unlike the campaigns of either Sanders or Warren, the Biden campaign has dropped its opposition to the formation of a super PAC, an independent political action committee that can raise unlimited sums from corporations, unions, and big donors.

Biden, 76, served as Vice President from 2009 to 2017 under Barack Obama.

According to a RealClearPolitics average of recent polls, he is currently leading Warren and Sanders by 5.4 points and 9.9 points, respectively.