Communications Minister Anika Wells has brushed off a warning from the US about draft laws threatening hefty fines for platforms that fail to protect Australians online.

Tech companies will face fines of more than $100 million for failing to take steps to prevent harmful content being shown to young people under the proposed digital duty of care.

Social media giants face US$78 million fines if they fail to protect young users from harmful content, Australia's prime minister said Tuesday as he unveiled draft laws reining in…