"We're inspired and grateful for all the work you've done and want you to know -- your fight is our fight," first lady Jill Biden said in a video appearance next to her husband.

President Biden -- along with top Senate and House Democrats Chuck Schumer and Nancy Pelosi, who both appeared in person -- highlighted a new climate package that is the most far-reaching legislation ever in the United States to spur clean energy.

But prime minister Mia Amor Mottley of Barbados warned that action against climate change cannot come quickly enough for islands such as hers.

"Yes, my friends, our time is running out," she said.

Thrash metal legends Metallica got the crowd headbanging with eight songs including a version of "Nothing Else Matters" featuring vocalist Mickey Guyton, who has been outspoken about her experiences as one of the most prominent Black women in country music.

Guests sought to raise awareness on an array of issues including women's rights, especially in light of major protests in Iran following the death of Mahsa Amini, who was allegedly beaten to death after her arrest by morality police who enforce clerical rulers' dress codes on women.

"I have seen my sisters forced to flee abuse, oppression and femicide globally, women like Mahsa Jina Amini," said Anuscheh Amir-Khalili, a refugee advocate in Berlin of Iranian descent.

"We must speak up for oppressed women. I stand here for them," she told the crowd.

European Union chief Ursula von der Leyen, appearing on stage, said, "We have to take care of our girls and our women. They deserve it."

She highlighted recent pledges by Europe including 600 million euros for food security in Africa, the Caribbean and the Pacific amid rising hunger in much of the world worsened by Russia's invasion of Ukraine.

Mariah Carey was introduced by leading ballerina Misty Copeland, who called the singer with her famed vocal range an inspiration, and was accompanied by a choreographed dance for her classic song "Hero."

Other performers included Maneskin, the new-generation Italian glam rockers who put on an energetic set, Spanish pop star Rosalia, and the Jonas Brothers, with Nick Jonas' wife, Indian screen star Priyanka Chopra, serving as master of ceremonies.