The Australian and New Zealand governments will talk with social media companies about how to stop their platforms being used to spread terrorist material in the wake of the Christchurch massacre.
Fifty people died in Friday's attack at two mosques on New Zealand's South Island and about 36 people are in hospital.
A 17-minute live video of the alleged attacker - Australian Brenton Harrison Tarrant - arming himself and entering a mosque where he started shooting was uploaded and shared online.
The 28-year-old also posted a 74-page "manifesto" online before the attack.
Leaders and police from both Australia and New Zealand have pleaded with people and the media to not share or watch the video.
Federal Opposition Leader Bill Shorten was scathing of social media giants who he says allow content to be shared that would normally cause legal action.
"If a newspaper wrote some of the stuff that you allow on your media platforms they'd be in court," he told reporters in Melbourne on Sunday.
"The big media platforms do have an obligation to better monitor and prevent hate speech."
Prime Minister Scott Morrison said Facebook had previously suspended "these sort of" live streams that were seen on Friday.
"Assurances were given that ... it could avoid this and clearly it hasn't," Mr Morrison told reporters in Sydney on Sunday.
He said there needed to be some "very real" discussions about how such content could exist on social media.
"We will be seeking to get assurances from the social media companies about their capabilities to ensure that this tool cannot be used by terrorists," Mr Morrison said.
The prime minister conceded it was "very difficult" to prevent images and videos from spreading once they had already been uploaded onto social media.
New Zealand Prime Minister Jacinda Ardern said her government did all it could to remove the online footage but in the end it had been up to the platforms to make sure it was deleted.
"There are further questions to be answered," Ms Ardern told reporters on Sunday.
"Whilst we might have seen action being taken here, that hasn't prevented it (the footage) being circulated beyond New Zealand shores."
It's an issue which extends beyond New Zealand and one which Ms Ardern insists she will discuss directly with Facebook.
Tarrant, from Grafton in NSW, is the only person charged with murder over the attack and has been remanded in custody until April 5.