From December 10, companies must take reasonable steps to find underage users and stop under-16s accessing social platforms and provide users an accessible complaints process.
Tech giants face fines of up to $50 million if they do not comply.
Meta, the company founded and led by Mark Zuckerberg, which owns platforms Facebook, Instagram, WhatsApp, Messenger and Threads, will introduce artificial intelligence (AI) supervision tools for parents in early 2026.
Parents will be able to turn off their children's access to one-on-one chats with AI characters on Meta's platforms, set time limits for interactions and see what topics they are chatting to the bots about.
"AI is evolving rapidly, which means we are going to need to constantly adapt and strengthen our protections for teens while listening and responding to concerns parents have about this new technology," a company statement issued on Saturday said.
"We hope today's updates bring parents some peace of mind that their teens can make the most of all the benefits AI offers, with the right guardrails and oversight in place."
The changes will be rolled out to the United States, England, Canada and Australia.
AI chatbots were "supercharging" the problem of bullying, Education Minister Jason Clare said.
"It's not kids bullying kids - it's AI bullying kids, humiliating them, hurting them, telling them they're losers, telling them to kill themselves," he told reporters on Saturday.
"I can't think of anything more terrifying than that ... that's what we're up against."
Meta previously announced it had updated AI experiences for teens to be guided by the PG-13 movie rating system to prevent minors from accessing inappropriate content.
Meta will also implement changes on Instagram to restrict content for users aged from 13 to 17 in line with PG-13 ratings.
Although it will come into effect ahead of Australia's social media ban for under-16s, the company said the change had not been implemented due to the looming restrictions.
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Kids Helpline 1800 55 1800 (for people aged 5 to 25)
