Earlier this month, Alabama's Republican governor signed into law the bill, which makes it a felony punishable with up to 10 years of imprisonment for providing voluntary medical treatments, including hormone therapy, puberty blockers and surgery to help align physical characteristics to the gender identity of a minor.

The Justice Department's complaint alleges that the "new law's felony ban on providing certain medically necessary care to transgender minors violated the equal protection clause" of the U.S. Constitution's Fourteenth Amendment.

The department asked the court to issue an immediate order to prevent the law from going into effect.

Civil rights groups, including the American Civil Liberties Union, had also vowed to challenge the law in court when it was signed.

"Transgender youth are a part of Alabama, and they deserve the same privacy, access to treatment, and data-driven health care from trained medical professionals as any other Alabamian," Tish Gotell Faulks, legal director, ACLU of Alabama, said in early April press release.

The Alabama law is among several measures targeting transgender youth that are advancing in Republican-led states ahead of the November mid-term congressional elections.

"I believe very strongly that if the good Lord made you a boy, you are a boy, and if he made you a girl, you are a girl," Governor Kay Ivey had said when she signed the bill into law. "We should especially protect our children from these radical, life-altering drugs and surgeries when they are at such a vulnerable stage in life."