Louisiana Gov. John Bel Edwards has vetoed a ban on gender-affirming care for most minors in the state, the latest Democratic governor to push back on a GOP-led legislature's efforts to restrict transgender youth's access to such treatments.

The move sets the stage for a battle with the legislature's Republican supermajority, which could vote to override his veto.

"It is unfathomable to think that in my last few months serving as governor of this state that I would sign into law a bill that categorically denies health care for children and families based on propaganda and misinformation generated by national interest groups," Edwards, who is term-limited, wrote in a veto letter dated Thursday, saying the bill harms children.

"I assessed the need for this bill based on Louisiana data and facts and read every word of this bill multiple times to determine if there was any possible merit to this bill. There is not," he continued later.

House Bill 648 would bar those under 18 in Louisiana from receiving gender-affirming surgeries, puberty blocking medications and hormone treatments, and punishes health care professionals that provide them with the revocation of their license for a minimum of two years.

Doctors who began providing such drug or hormone therapy to a minor before January 1, 2024, would be allowed to continue providing care through December 1, 2024, if they determine that "immediately terminating the minor's use of the drug or hormone would cause harm to the minor."

The bill passed the Republican-led legislature with strong support in early June -- with the House voting 75-25 in favor and some Democrats crossing party lines in the Senate to advance the legislation by a vote of 29-10.

Gender-affirming care spans a range of evidence-based treatments and approaches that benefit transgender and nonbinary people. The types of care vary by the age and goals of the recipient, and are considered the standard of care by many mainstream medical associations.

Though the care is highly individualized, some children and parents may decide to use reversible puberty suppression therapy. This part of the process may also include hormone therapy that can lead to gender-affirming physical change. Surgical procedures prohibited under the measure, however, are not typically done on children and many health care providers do not offer them to minors.

No such surgeries were performed on Louisiana minors enrolled in Medicaid from 2017 to 2021, according to a report from the state Department of Health, which found that few minors, between 21 and 57 each year, received chemical treatment during the same time period.

Proponents of the legislation have expressed concern over long-term outcomes of the treatments. But major medical associations say that gender-affirming care is clinically appropriate for children and adults with gender dysphoria -- a psychological distress that may result when a person's gender identity and sex assigned at birth do not align, according to the American Psychiatric Association.

The issue has become a flashpoint with more than a dozen other states placing bans on gender-affirming care for minors on the books this year, largely in governments with Republican trifectas -- though the legality of such laws are being questioned as a federal judge last week struck down a 2021 Arkansas measure.

Democratic governors have pushed back on Republican-led efforts to restrict the treatments with varying degrees of success -- Kansas Gov. Laura Kelly successfully blocked a ban while state lawmakers overrode Kentucky Gov. Andy Beshear's veto.

At a news conference following the Louisiana legislative session's adjournment on June 8, Edwards said it was his "expectation" to veto a slate of anti-LGBTQ bills, including HB 648.

"I will tell you that on those issues, the judgment of history, I believe, will be very clear. It will be as clear as the judgment of history has been on those who didn't want civil rights in the 50s, for example. But I am not going to wait until then to say that it's wrong. My judgment today is that those bills are wrong," he said.

Edwards advised Louisianans to "focus on the real problems," rather than "pick on very small minorities who happen to be comprised of the most vulnerable, fragile children in our state, those most likely to engage in suicidal ideation and suicidal attempts. There's nothing great in that."

The governor declined to take action on an anti-trans sports ban last year, claiming at the time that while he opposed the legislation, it was clear to him that lawmakers would move to override him if he issued a veto.

Republicans again hold strong enough majorities in the state's House and Senate to override vetoes from the governor after Louisiana's longest-serving legislator switched in March from the Democratic Party to the Republican Party.

The legislature can consider the bill in a "veto session" where the House and Senate reconvene 40 days after the end of the normal legislative session -- which adjourned June 8. To override the veto, supporters of the ban would need a two-thirds majority in both chambers.

Lawmakers could, however, halt the convening of the veto session "if a majority of the elected members of either house declare in writing that a veto session is unnecessary," according to state law.

Republican state Rep. Gabe Firment, the bill's sponsor, told CNN in a statement ahead of the governor's action that his "biggest concern is that term-limited state senators will be persuaded by the governor to not show up for a veto override session."

"However, grassroots groups and citizens across the state are already mobilizing in anticipation of a gubernatorial veto and the people of Louisiana have made it clear that our kids are worth fighting for," he added.

The No. 2 Republican in the state House, Rep. Tanner D. Magee, said in a statement to CNN last week that whether GOP lawmakers will follow through with a veto session was "unclear right now. We are still talking to members and assessing their desires."

Not all Republicans, however, have supported HB648. The bill was temporarily stalled in a state Senate committee last month, with the panel's Republican chairman casting a tie-breaking vote against the legislation.

"I've always in my heart of hearts, believed that a decision should be made by a patient and a physician," state Sen. Fred Mills said, explaining his vote.

The state Senate revived the bill the following week by recalling the bill from Mills' committee and reassigning it to another, where it was passed.