(NewsNation) — Oklahoma Gov. Kevin Stitt signed an executive order directing state agencies to use narrow definitions of “female” and “male” Tuesday, a move LGBTQ+ advocates say is an attack on transgender rights.

Executive Order 2023-20 states that “female,” when used in reference to a “natural person” shall be defined as a person “whose biological reproductive system is designed to produce ova.” “Male” should be used to refer to someone whose “biological reproductive system is designed to fertilize the ova of a female,” the order says.

“Woman” and “girl,” under the order, are specifically defined as “natural persons who are female,” while “man” and “boy” reference those who are male. Schools and other state agencies are ordered to use these definitions when collecting vital statistics.

In addition, schools are being ordered to provide dedicated restrooms and locker room facilities for boys and girls, respectively.

This is the latest act targeting transgender rights in a state that already has laws on bathroom use, health care and sports teams for trans people.

Earlier this year, Stitt signed a bill into law making it a crime for health care workers to provide gender-affirming medical care for minors. He’s also previously signed measures to prohibit transgender girls and women from playing on female sports teams and prevent trans children from using school bathrooms that correspond to their gender identity.

“Today we’re taking a stand against this out-of-control gender ideology that is eroding the very foundation of our society,” Stitt said at a news conference Tuesday. “We are going to be safeguarding the very essence of what it means to be a woman.”

“Oklahomans are fed up with attempts to confuse the word ‘woman’ and turn it into some kind of ambiguous definition that harms real women,” he added.

NewsNation partner The Hill reports that Kansas, Tennessee, North Dakota and Montana also narrowed the definition of sex in state law in legislation dubbed as “LGBTQ Erasure Acts” by advocates. 

A number of organizations were quick to condemn Oklahoma’s new order, including the state’s chapter of the American Civil Liberties Union, which announced it is pursuing a lawsuit challenging it.

The lawsuit, also filed by the national ACLU, Lambda Legal and the law firm Jenner & Block LLP, a group of families with transgender adolescents and medical providers who support trans youth, say the executive order “unjustly and unfairly targets them” and violates their rights under the Equal Protection Clause of the 14th Amendment.”

“Every Oklahoman should have the freedom to access the care they need to survive and thrive, but once again, instead of deciding to boldly lead our state, Gov. Stitt and members of the legislator have decided to risk the lives of one of our most vulnerable populations, to score political points with their base,” Megan Lambert, ACLU of Oklahoma’s legal director, said in a statement.

Calling the executive order a “thinly veiled attack” that codifies discrimination against transgender women, Nicole McAfee, executive director of Freedom Oklahoma, said it was neither about rights or protecting women.

House Democratic Leader Cyndi Munson said the governor is using “partisan, polarizing politics” to further divide Oklahomans.

“Once again, the Republican supermajority continues their government overreach by infringing on the rights of citizens,” said Munson.

The Associated Press contributed to this report.