President Donald Trump’s signing of an executive order barring transgender athletes from competing in women’s sports triggered outrage among those who advocate for transgender women in sports.

In a White House ceremony Wednesday, Trump, surrounded by female athletes of all ages and several lawmakers, signed the measure, called “Keeping Men Out of Women’s Sports.”

The order interprets a person’s gender as the one designated at birth and recorded on a birth certificate, and it gives federal agencies authority to enforce the order barring athletes considered male at birth from competing in women’s sports.

“We will defend the proud tradition of female athletes and we will not allow men to beat up, injure and cheat our women and our girls,” Trump said. “From now on, women’s sports will be only for women.”

There are already numerous lawsuits in the works over other gender-related executive orders signed by Trump.

The National Center for Lesbian Rights is involved in some of those cases and blasted the new order.

“The attempts to try to attack these children, to try to undermine the abilities of adults and school districts and athletic associations to make judgements about how these children should be able to play and participate is just an outrageous attack by politicians who have an agenda of hate,” National Center for Lesbian Rights senior attorney Amy Whelan said.

A player on San Jose State University’s women’s volleyball team was singled out by Trump during his presidential campaign. Numerous teams forfeited games rather than play the Spartans.

The university issued a statement Wednesday saying it remains fully committed to wellness, safety, and privacy of students, faculty, and staff by fostering a supportive and caring environment. The university has never formally confirmed a transgender player is on the team.

The order, as with some of the other Trump executive orders, is expected to be challenged in court.

Beyond that, the order also directs the secretary of state to lobby the International Olympic Committee to enact a similar ban and sets up meetings with private sports organizations to lobby them to enact bans as well.