JACKSON, Miss. (NewsNation Now) — Mississippi Republican Gov. Tate Reeves signed a bill Thursday to ban transgender athletes from competing on girls or women’s sports teams.

Mississippi is the first state this year to enact such a ban, after a federal court blocked a similar Idaho law last year. Lawmakers in more than 20 states are proposing restrictions on athletics or gender-confirming health care for transgender minors this year.

Conservative lawmakers are responding to an executive order by Democratic President Joe Biden that bans discrimination based on gender identity in school sports and elsewhere. Biden signed it Jan. 20, the day he took office.

Gov. Reeves has three daughters who play sports, and he said on Twitter that Mississippi’s bill would “protect young girls from being forced to compete with biological males for athletic opportunities.”

“But for the fact that President Biden as one of his first initiatives sat down and signed an executive order — which, in my opinion, encourages transgenderism amongst our young people — but for that fact, we wouldn’t be here today,” Reeves said during a ceremony in the Mississippi Capitol, where he was joined by legislators who supported the bill.

Republican legislators who pushed the bill gave no evidence of any transgender athletes competing in Mississippi schools or universities.

Chase Strangio, a transgender-rights attorney with the national ACLU, said the Mississippi bill “is very vague and seemingly unenforceable.”

“Unfortunately, there is already rampant discrimination against trans youth in Mississippi, which means people are already driven out of sport,” said Strangio. “Gov. Reeves’s statement makes clear that this isn’t about sports at all, this is about attacking trans youth and stopping kids from being trans — a dangerous project with deadly consequences.”

Alphonso David, president of the LGBTQ civil rights organization Human Rights Campaign, said in a statement Thursday that the Mississippi law could lead to more bullying of transgender people.

“This law is a solution in search of a problem, and legislators in Mississippi have not provided any examples of Mississippi transgender athletes gaming the system for a competitive advantage because none exist,” David said.

Reeves has three daughters who play sports and he said March 4 on Twitter that Mississippi’s bill would “protect young girls from being forced to compete with biological males for athletic opportunities.”

The Mississippi Senate passed the bill Feb. 11, and the House passed it March 3. The votes were largely along party lines, with most Republicans supporting the bill and most Democrats either opposing it or refraining from voting.

Mississippi’s ban is set to become law July 1, although a legal challenge is possible.

South Dakota’s governor, Kristi Noem, said earlier this week that she will sign a bill to bar transgender girls and women from participating in female sports leagues. Though, whether it’ll ultimately take effect in the state will likely be decided in federal court.

Only one state, Idaho, has enacted a law curtailing trans students’ sports participation, and that 2020 measure is blocked by a court ruling.

The Associated Press contributed to this report.