"Harry Potter" author JK Rowling launched the US arm of her nonprofit, Lumos, on Thursday. 

The charity's mission is to support disadvantaged children and their families by keeping them together and out of institutions. 

Rowling attended a lighting ceremony on the observation deck of the Empire State Building to commemorate the launch, and expressed confidence that her organisation will solve "the problem of institutionalisation" by 2050.

"There are decades of research showing that institutionalising children is inherently damaging," Rowling told the Associated Press. "It's damaging physically, it's damaging psychologically, it's damaging emotionally."

The author founded Lumos in Europe in 2005, and the organisation has offices in London, Bulgaria, Prague, Moldova, Belgium, and Washington DC. 

In addition to an increased US presence, Lumos is reaching Latin America and the Caribbean. Rowling said the nonprofit, named after a "Harry Potter" spell that produces light, has been invited to work in Haiti. Many of the Haitian children in orphanages have living parents who are unable to afford their care, she explained. 

Lumos reported that eight million children are in group homes and orphanages around the world, instead of remaining connected to their families and communities. Rowling sees Americans' charitable giving as a great opportunity to impact child welfare policies around the world. 

"America gives a phenomenal amount of money, and we would love to see that aid and that philanthropy channelled toward systems that support children within their families rather than the separation of families," she said.

Rowling is also working on the third book in her crime series under the pen name Robert Galbraith, and a screenplay for her 2001 book "Fantastic Beasts and Where to Find Them." The latter is a spinoff of the popular "Harry Potter" series.