Prime Minister Jacinda Ardern's message after El Paso shooting, NZ links

Jacinda Ardern has spoken out about the March 15 mosques shootings in the wake of reports that the El Paso killer supported the man accused of the Christchurch massacre, who preached white nationalism.

"I think New Zealand would have only one memory that they would wish there to be around March 15 and that would be the absolute resolution of the entire country against acts of hatred, against acts of violence and against acts of terrorism," the Prime Minister told reporters at Parliament.

"We would also probably only wish for it to be remembered for the unity that New Zealand displayed alongside the Muslim community. We would wish for it to remembered for nothing else," she said.

The shootings at an El Paso Walmart store in the state of Texas left 20 people dead. El Paso is a city right on the border with Mexico.

Rene Aguilar and Jackie Flores pray at a makeshift memorial for the victims of the mass shooting at a shopping complex in El Paso, Texas. Photo / AP

AP reported that El Paso police were investigating an online post shortly before the shooting, possibly by the suspect. It expressed concern about an influx of Hispanic voters replacing white ageing white voters in Texas which could turn the state from Democrat to Republican.

The document also expressed support for the man accused of killing 51 people at the two Christchurch mosques in March.

When Ardern was asked what more she could do stop white nationalists, she said it was a global challenge.

"Of course we can do what we can to defeat acts of hatred and violence and racism in our domestic areas and that's our responsibility but I think as an international community we have to also be united against acts of hatred, violence and terrorism."

She hinted that more countries will be signing up to the "Christchurch Call to Action" when she attends leaders' week at the United Nations in September.

The Christchurch Call is a pledge by countries and tech companies to eliminate terrorist and violent extremist content online.

Seventeen countries, the European Union and eight major tech companies have signed up to the accord launched in Paris in May.

Referring to shutting down online channels such that promote violence and white nationalism, Ardern said: "We do have a sense of responsibility to try and create that framework but New Zealand cannot do that alone. These are international platforms. That's why we have been trying to work globally on some of these issues.

"Interest has been ongoing but rather than just have individual countries sign up on an ad hoc basis, we will be looking to do announcements around additional signatories when we gather together again in September."

Nato Secretary General Jens Stoltenberg who is visiting New Zealand, visited the Al Noor Mosque today.

He was Prime Minister of Norway in 2011 when 69 mainly young people were shot and killed by Anders Breivik.

Stoltenberg told 1 News that the Christchurch attacks had taught the world there were "many different forms" of terrorism.

"These attacks are committed by lone wolves but they are at the same time connected, because they use each other as inspiration and they refer to each other in the different manifestos and I think we have to fight terrorism in many different ways," he said.

"Partly it's about police, security, intelligence. Nato has a role to play, but it's about attitudes, values, what we all stand up for our open and free society for tolerance."

Nato, the North Atlantic Treaty Organisation, is a post World War II security alliance including the United States, Canada, Britain, Germany, France and Turkey.