The Democratic US House speaker took the stage to speak about the climate crisis, with some booing being heard from the audience, videos from the event show.
“As speaker of the House, I am here to thank you for your dazzling advocacy, entrepreneurial thinking, and determination as global citizens,” she said.
Others in the crowd cheered for the California lawmaker while some could be heard heckling. The sounds from the audience continued for most of her speech.
“It’s thanks to your help that the United States recently enacted historic climate legislation, which will be a game changer,” the speaker said. “It will slash carbon pollution by 40 per cent by 2030, it will give a historic, an historic $370bn to fight the climate crisis.”
Some in the crowd could be heard yelling “let’s go” – seemingly wanting the concert to continue.
Ms Pelosi pressed on, saying that the legislation would lead to “better water and air for our children” and “better-paying jobs and lower energy bills for their parents”.
Democrats passed a healthcare and climate spending package – the Inflation Reduction Act – last month. It includes $369bn for improving the supply of renewable energy and restricting emissions, according to The Guardian.
Towards the end of her speech, the speaker noted that her grandchildren Paul and Thomas were in the crowd and that she had pledged to keep her time on stage short so they could get back to the music.
The San Francisco Democrat also appeared at the Global Citizen Festival in 2016, according to The New York Post.
This time, the speaker appeared alongside actor and activist Priyanka Chopra Jonas, one of the hosts of the show.
The Global Citizen Festival takes place annually and gives out free tickets to tens of thousands of people who work to end extreme poverty, The Post noted.
“Thank you, @SpeakerPelosi for recognizing Global Citizens all around the world who took action in support of the new, historic climate legislation in the US!” the organisation tweeted.
This year’s festival featured artists such as Metallica, Usher, Mariah Carey, and the Jonas brothers.