Jennifer Lopez invited her mum to join her for a mini duet onstage during the Global Citizen's VAX Live: The Concert to Reunite the World event on Sunday.

Filmed at the SoFI Stadium in Los Angeles, the superstar was partway through performing when she decided to introduce the audience to her mother, Guadalupe Rodriguez, before launching into a rendition of Neil Diamond's classic hit Sweet Caroline.

Explaining how the Covid-19 pandemic had forced the close pair to spend months apart, Jennifer told the crowd, "(I) didn't even get to spend Christmas with my mum this year - first time in my whole life. We've been away (for) too long, but she's here with me tonight and she is vaccinated."

"And when I was thinking about what song to sing tonight, I remembered the song she used to always sing to me when I was a baby," she continued. "So, if you would indulge me, I'd love to sing that one tonight."

Guadalupe then shared how she used to customise the lyrics to sing "Sweet Jennifer" to her baby girl.

"OK, we're going to sing that. Let's do it like a lullaby. Sing it to them just like you used to sing it to me, OK?" J.Lo instructed her mum, before starting the duet.

Elsewhere in her set, the singer/actress celebrated the fact everyone in attendance could be "all here in the same room", as she also saluted the "beautiful" individuals taking part.

"We've been away from our loved ones for too long, but we're back," the 51-year-old smiled. "But while it's getting better for us, there are people all over the world, especially in Africa, India and in the Latin world who still need our help and our vaccines. That's why we're here tonight."

Selena Gomez hosted the big fundraising gig, while Oscar winner H.E.R., the Foo Fighters, Eddie Vedder, and J Balvin also hit the stage.

There were additional appearances from U.S. President Joe Biden and First Lady Dr. Jill Biden, Vice President Kamala Harris, as well as the likes of Olivia Munn, Chrissy Teigen, Sean Penn, Ben Affleck, and Prince Harry - who delivered an impassioned speech, encouraging people to work together to help end the Covid-19 pandemic by improving access to testing facilities and vaccinations to those in poverty-stricken nations.

Global Citizen's VAX Live: The Concert to Reunite the World is set to air in the U.S. on Saturday.