Thousands of people gathered in a swampy Central Park for a concert urging global development aid, with Jungkook of BTS fame and Brazil's Anitta highlighting the marathon show's first half.

Jungkook had the poncho-clad crowd screaming and swaying along as he serenaded them with hits including "Still With You" during the Global Citizen Festival marked by a chilly, persistent rain.

Wearing acid-wash jeans and a brown shirt, the megastar told fans it was necessary to "make an impact together to make sure everyone, everywhere has access to their basic rights like food and education."

He wasn't billed as a headliner but Jungkook was a major draw of the night: many drenched concertgoers streamed out of the park just after his set ended, even though the evening was set to continue for another three hours.

Earlier in the evening Anitta brought her impressive twerks and dance party of a show to the stage, performing hits including her recent "Funk Rave."

Brazil's biggest pop star called attention to the importance of protecting the Amazon rainforest, reminding fans it's "the lungs of our planet."

She also said just prior to kicking off her booty-shaking set that governments must do more to "protect the people there, the indigenous people, the communities there… whose only reality is the Amazon."

And rappers including Busta Rhymes and  Common put on a 50th anniversary of hip hop tribute, one of many that has been put on across the city in recent months.

Still to come are headliners Lauryn Hill and the Red Hot Chili Peppers.

Fight against hunger

Taking place since 2012 as world leaders gather in New York for the UN General Assembly, Global Citizen distributes tickets for free to supporters who pledge to take action such as sending letters to their governments in support of development aid.

Pledges came from leaders including French President Emmanuel Macron, who announced via video message a $150 million commitment to the International Fund for Agricultural Development.

"We have to fight together against poverty, climate change, and for biodiversity," Macron said. "This is why we want to take our part as well."

The Rome-headquartered IFAD is an arm of the United Nations aimed at addressing poverty and hunger in rural areas of developing countries.

Global Citizen welcomed Macron's commitment in a statement, adding that "much more needs to be done to provide crucial support to millions of smallholder farmers around the world, who produce 70 percent of food in low and middle-income countries."

The institution urged governments to double their climate adaptation funding and make sure IFAD reaches its funding target of $2 billion by the end of 2023.

Along with Macron, they said Norway had pledged $90 million to IFAD.