Stevie Wonder knelt before a packed New York festival Saturday in a protest for peace as he led stars and politicians in pressing for sustained aid to eliminate the world's worst poverty.

On a balmy late summer night, thousands converged on Central Park for the live-broadcast Global Citizen Festival which hands out tickets for free to fans who take actions such as petitioning their governments to support development assistance.

With President Donald Trump proposing sweeping aid cuts, the concert had set a goal of building political momentum in the world's largest donor nation. But in a deeply divided United States, another Trump controversy came to the forefront.

Wonder took the stage and knelt, emulating a gesture popularized by NFL quarterback Colin Kaepernick during the national anthem to denounce racial injustice. Trump on Friday angrily denounced such protests, using profanity to demand that teams fire the athletes.

"Tonight, I'm taking a knee for America," the blind soul legend said as took to the ground, his son Kwame Morris clutching his arm.

Wonder also voiced worry over the increasingly personal venom between Trump and North Korean strongman Kim Jong-Un.

"We could lose the ultimate video game -- of life -- losing sight that weapons are real, and rhetoric is dangerous, whether it be from a superpower in North America or a superpower in North Korea," Wonder said.

Wonder jammed through more than an hour of his best-loved songs before turning his ever-powerful belting voice to the 1985 charity singalong "We Are the World" as well as "Imagine," the peace anthem by John Lennon who was assassinated a short stroll away.

The 67-year-old Wonder closed by bringing up a visibly star-struck Pharrell Williams, singing together a funk-heavy take of "Get Lucky," which Williams co-wrote for Daft Punk, as well as the younger artist's ode to optimism "Happy."

- Green Day take aim -

The diverse but heavy-hitting lineup also featured chart-topping electronic duo The Chainsmokers, rising soul star Andra Day, folk rockers The Lumineers and young Canadian pop songwriter Alessia Cara -- who, in a feat of organization, also performed Saturday in Toronto at the Invictus Games for wounded soldiers and veterans.

Punk rock greats Green Day injected politics as well, with frontman Billie Joe Armstrong weaving Trump into the lyrics of "American Idiot," the band's high-octane 2004 indictment of US media culture.

Green Day turned down the volume for a second set of "Wake Me Up When September Ends" and "Good Riddance (Time Of Your Life)," set to a slideshow from UNICEF to show the still severe human impact of AIDS.

French President Emmanuel Macron addressed the festival by video, promising to help raise more than $1 billion for the Global Partnership for Education before a February 8 conference in Senegal. 

The group brings together the public and private sectors to expand schools -- seen as critical to reducing poverty.

"It's all about education precisely to fight against terrorism, fundamentalism," said Macron, introduced by Senegal's ambassador to the United Nations which is holding its annual General Assembly.

"It's all about education to help women to build their lives, to help people to have a decent life."

The partnership has a goal of $3.1 billion in funding for 2018 through 2020, of which $2 billion has already been committed.

- Pressure to stop cuts -

Denmark's minister for development cooperation, Ulla Tornaes, announced to the festival that her government would next year double to $110 million its international funding for women's sexual and reproductive health.

"When some countries stop fighting for women's rights, we intensify ours," she said to applause.

Trump, as part of his "America First" ideology, has proposed slashing foreign aid by one-third although he faces stiff opposition in Congress.

Aid advocates point out that extreme poverty has fallen by half since 1990, although more than 750 million people live on less than $1.90 a day, according to the World Bank.

Representative Charlie Dent, a leading moderate in Trump's Republican Party, said that Global Citizen had triggered some 400,000 calls to the US Congress to preserve aid -- and voiced hope the pressure would work.

"Foreign assistance is good for humanity and it advances America's interests around the world," Dent told the festival.