A first-of-its-kind ban on transgender athletes in New York state is happening on Long Island.

"If there is a league or team that advertises themselves to be women's or girls, then biological males will not be able to compete," said Nassau County Executive Bruce Blakeman, who signed an executive order Thursday which prevents transgender girls and women from participating on girls' and women’s teams. 

Blakeman said the order is not meant to exclude anyone, but to even the playing field for athletes assigned female at birth.

“There are women and girls that spend a tremendous amount of time and effort to excel and compete in their sports that are women’s sports,” Blakeman said. “And it is an unfair advantage for someone who is a biological male to compete against a biological female.”

Sports leagues, including ones from New York City, will need to comply with the new measure or lose access to Nassau County-run facilities. Activists say the order discriminates against trans individuals.

“It’s essentially saying if you’re a trans girl, you can’t be part of those spaces. It’s excluding people from public life,” said Bobby Hodgson, director of LGBTQ Rights Litigation at the NYCLU.

In New York state, the Gender Expression Non-Discrimination Act prohibits discrimination against transgender individuals in employment, housing and public accommodations.

“It’s a reflection here in New York of what’s happening around the country and the ways in which trans people are targeted. I only hope that we can offer some comfort here in New York state. We have very clear laws that this cannot be happening and this will not stand,” Hodgson said.

In a tweet, Schools Chancellor David Banks wrote, “New York City Public Schools strongly condemns this transphobic order, and we are assessing the practical implications for our athletes.”

Gov. Kathy Hochul, State Attorney General Letitia James and the New York Civil Liberties Union have all called the ban illegal, and are exploring legal action.