Texas Governor Greg Abbott signed into law Friday a ban on treatment for transgender minors, making his state the largest in the United States to place restrictions on youth access to such care.

Abbott followed in the footsteps of Florida Governor Ron DeSantis, a fellow Republican, who signed a similar bill in May. Texas and Florida are the second and third most populous states in the US.

The Texas law bans medical professionals from prescribing hormone blockers or performing gender transitioning surgeries to anyone under 18 years old. It comes into effect on September 1.

The legislation includes an exception for minors already receiving puberty blockers or hormone therapy, but requires that they “shall wean off the prescription drug over a period of time and in a manner that is safe and medically appropriate.”

Transgender rights have increasingly become a hot-button issue in US politics, with Democrats decrying moves such as the Texas and Florida laws as encroaching on fundamental rights.

On Friday, the American Civil Liberties Union of Texas said it would be filing a suit against the state’s ban.

“Abbott can’t stop trans youth from thriving in Texas – and we’ll take him to court to make sure of it,” the rights organization said in a tweet.

Following the passage of the bill by the Texas state legislature last month, US rights organizations – including ACLU of Texas, as well as Lambda Legal and Transgender Law Centre – said the law banned “medically necessary health care.”

“Texas Senate Bill 14 bans the only evidence-based care for gender dysphoria for transgender people under 18 and aims to strip doctors of their medical licenses for providing their patients with the care they know to be medically necessary,” the groups said in a statement.

More than a dozen Republican-led states have passed similar bans in recent months.

In March, President Joe Biden said that such “attacks” on transgender rights were “un-American and must end.”

More than half of transgender and nonbinary youth in Texas had seriously considered suicide during 2022, according to a survey that year by the Trevor Project, a nonprofit organization engaged in suicide prevention efforts among LGBTQ+ youth.

“LGBTQ young people are not inherently prone to suicide risk because of their sexual orientation or gender identity, but rather placed at higher risk because of how they are mistreated and stigmatized in society,” the survey said.