The White House has snubbed the Christchurch Call to Action, but says it stands with the international community in condemning terrorist and violent extremist content online.
"While the United States is not currently in a position to join the endorsement, we continue to support the overall goals reflected in the call. We will continue to engage governments, industry, and civil society to counter terrorist content on the internet," the White House said in a statement.
The New Zealand Government has been lobbying the US to endorse the Christchurch Call to Action, due to be released at 4am (NZT), for several weeks, including having government officials visit the USA.
It is expected to be signed by at least 10 governments and several major tech companies, but the absence of the US is seen as denying a stronger mandate.
US President Donald Trump also did not accept an invitation to be in Paris for today's summit.