Prime Minister Scott Morrison launched a major assault on internet behemoths just hours before flying to Rome to attend the G20 conference.

Mr Morrison believes the companies are publishers rather than platforms which need to be more responsible for bullying, defamation and people being targeted online.

"Particularly, when they allow people to anonymously go on their platforms and publish their vile rubbish," he told reporters in Canberra on Thursday.

"That's not freedom of speech, that's just cowardice and we cannot have that thrown up on our social media platforms to Australians in this country."

He pointed to a global leaders statement released at a G20 conference after the Christchurch massacre, which led to action on terrorists not using social media broadcasts.

"But they're still being used as a weapon right now, destroying the mental health of our young people, destroying lives," the prime minister said.

The government this week released draft laws which require platforms to obtain parental consent for users under the age of 16 and introduce a range of tougher penalties for not protecting children.

"Australia is leading in this area and I'll be raising that with other G20 leaders when I'm there because we have to go further than we are now," Mr Morrison said.

He said the world was reaching a critical point in its health and economic recovery from the coronavirus pandemic which would also be discussed.

The prime minister said he would welcome any discussion with French President Emmanuel Macron, who has refused to take Mr Morrison's calls after Australia tore up a $90 billion submarine contract.

"We're like-minded, we share values and we share the objectives and aspirations for the Indo-Pacifc region of which France isn't just an observer - they're a participant."

Along with Australia the G20 comprises Argentina, Brazil, Canada, China, France, Germany, India, Indonesia, Italy, Japan, Korea, Mexico, Russia, Saudi Arabia, South Africa, Turkey, the United Kingdom, the United States, and the European Union.

The leaders of China, Russia and Japan are not expected to attend the G20 summit.

Australian Associated Press