'Hi, hi, hi, hi, sorry to keep you,' the California senator says on the call. 'No, that's alright, you ready to get to work?' Biden asks. A seemingly surprised Harris then responds, 'Oh my God. I am so ready to go to work.'
Harris will kick off her time as a vice presidential candidate with a joint appearance with Biden in Wilmington, Delaware late Wednesday afternoon - and on Friday she'll speak at a conference marking the 100th anniversary of the 19th Amendment on the same day as the Duchess of Sussex, Meghan Markle.
The conference is sponsored by The 19th, a non-profit news organization that covers the intersection of gender, politics and policy.
Other speakers include the Democrats' 2016 nominee Hillary Clinton, who was the first woman to ever top a presidential ticket.
The announcement of Harris marked the third time a female candidate was selected for veep and the first time a woman of color was chosen.
Other women speaking at the conference include two other vice presidential hopefuls: former Georgia gubernatorial candidate Stacey Abrams and Illinois Sen. Tammy Duckworth, along with former 2002 presidential hopeful, Rep. Tulsi Gabbard.