SACRAMENTO, Calif. (AP) -- California, home to some of the largest technology companies in the world, would be the first U.S. state to require mental health warning labels on social media sites if lawmakers pass a bill introduced Monday.

The legislation sponsored by state Attorney General Rob Bonta is necessary to bolster safety for children online, supporters say, but industry officials vow to fight the measure and others like it under the First Amendment. Warning labels for social media gained swift bipartisan support from dozens of attorneys general, including Bonta, after U.S. Surgeon General Vivek Murthy called on Congress to establish the requirements earlier this year, saying social media is a contributing factor in the mental health crisis among young people.

"These companies know the harmful impact their products can have on our children, and they refuse to take meaningful steps to make them safer," Bonta said at a news conference Monday. "Time is up. It's time we stepped in and demanded change."

State officials haven't provided details on the bill, but Bonta said the warning labels could pop up once weekly.

Up to 95% of youth ages 13 to 17 say they use a social media platform, and more than a third say that they use social media "almost constantly," according to 2022 data from the Pew Research Center. Parents' concerns prompted Australia to pass the world's first law banning social media for children under 16 in November.

"The promise of social media, although real, has turned into a situation where they're turning our children's attention into a commodity," Assemblymember Rebecca Bauer-Kahan, who authored the California bill, said Monday. "The attention economy is using our children and their well-being to make money for these California companies."

Lawmakers instead should focus on online safety education and mental health resources, not warning label bills that are "constitutionally unsound," said Todd O'Boyle, a vice president of the tech industry policy group Chamber of Progress.

"We strongly suspect that the courts will set them aside as compelled speech," O'Boyle told The Associated Press.

Victoria Hinks' 16-year-old daughter, Alexandra, died by suicide four months ago after being "led down dark rabbit holes" on social media that glamorized eating disorders and self-harm. Hinks said the labels would help protect children from companies that turn a blind eye to the harm caused to children's mental health when they become addicted to social media platforms.

"There's not a bone in my body that doubts social media played a role in leading her to that final, irreversible decision," Hinks said. "This could be your story."

Common Sense Media, a sponsor of the bill, said it plans to lobby for similar proposals in other states.

California in the past decade has positioned itself as a leader in regulating and fighting the tech industry to bolster online safety for children.

The state was the first in 2022 to bar online platforms from using users' personal information in ways that could harm children. It was one of the states that sued Meta in 2023 and TikTok in October for deliberately designing addictive features that keep kids hooked on their platforms.

Gov. Gavin Newsom, a Democrat, also signed several bills in September to help curb the effects of social media on children, including one to prohibit social media platforms from knowingly providing addictive feeds to children without parental consent and one to limit or ban students from using smartphones on school campus.

Federal lawmakers have held hearings on child online safety and legislation is in the works to force companies to take reasonable steps to prevent harm. The legislation has the support of X owner Elon Musk and the President-elect's son, Donald Trump Jr. Still, the last federal law aimed at protecting children online was enacted in 1998, six years before Facebook's founding.