Adam Lambert and Brian May of Queen perform onstage at the 2019 Global Citizen Festival.

The legendary band Queen and glam frontman Adam Lambert led a packed Central Park on Saturday in mobilising world governments to pledge international aid to eradicate extreme poverty and tackle climate change.

An estimated 60,000 people thronged the iconic Manhattan green space for the Global Citizen Festival, an unofficial exclamation point to the United Nations General Assembly which distributes free tickets to people who have worked towards the greater social good.

An estimated 60,000 people thronged the iconic Manhattan green space for the Global Citizen Festival.

Frontman Adam Lambert, who has toured with the band for some eight years, led the charge as veteran Roger Taylor helmed the drums as guitarist Brian May delivered his signature anthemic guitar solos.

The flamboyant Lambert went through a series of dramatic costume changes, finishing the show wearing a crown and a bright red military-esque uniform, as May dropped his long trench coat to reveal a T-shirt featuring the image of Queen's original lead singer Freddie Mercury, who died in 1991.

Like many of the other performers, Lambert used the moment to urge environmental protection.

Like many of the other performers, Lambert used the moment to urge environmental protection.

Believe in change

Prior to the Queen performance, Hollywood A-lister Leonardo DiCaprio made a surprise appearance to praise youth activists, including the Swedish teenager Greta Thunberg, who have taken to the streets and addressed world leaders in leading a global climate movement.

"Millions of individuals did more than simply walk out of their schools and places of employment. They took a stand," DiCaprio said. "They set an example of true leadership that our planet so desperately needs."

Agence France-Presse