Her fellow countrymen seemed to want to prove her right by volunteering acts of kindness.
"Love always wins over hate".
Wearing a black headscarf, Ms Ardern was a source of solace for Muslim Kiwis, telling them the entire country was united in grief.
New Zealand has raised its security threat level to the highest.
On Saturday, Christchurch Hospital said 39 people remained in hospital, 11 of them in intensive care.
Tarrant seemed "as normal as anyone else" and had "certainly" never mentioned anything about his beliefs about Muslims, the club's vice president, Scott Williams, said.
"I'm so proud of what they've done", he said.
Leaning on the shoulders of her friend, Imran's wife Akhtar cried as she held up her mobile phone with an image of her husband.
"She came here for the peace.now she is shocked", he said, adding his mother was too afraid to leave her house.
'Those decisions have yet to be taken, ' he told Radio New Zealand. They have not heard from him since. He also published a 74-page white nationalist manifesto in which he denounced Muslims and called immigrants "invaders".
Most of the dead were killed at the Masjid Al Noor mosque on Deans Avenue, before gunfire broke out at Linwood Masjid six kilometres away.
At least 49 people were killed in Friday's attack.
Facebook, Twitter and Google scrambled to take down the gunman's video, which was widely available on social media for hours after the bloodbath. He also had more assault weapons in the trunk of his vehicle, along with what appeared to be explosives.
"While work is being done as to the chain of events that led to both the holding of a gun license and the possession of these weapons, I can tell you one thing right now: our gun laws will change", said Ardern.
Fuller says Tarrant has spent little time in Australia in the past four years and Acting Deputy Police Commissioner Mick Willing says Tarrant was only known to police for "minor traffic matters'". One man has been charged with murder.
"Those decisions have yet to be taken, but the Prime Minister has signaled that we are going to look at that issue", Parker told Radio New Zealand.
"Rhetoric of racism, division and extremism has no place not only in New Zealand but I would say in a society as a whole". But it has one of the lowest gun homicide rates in the world.
During a Saturday press conference, Ardern said the gunman had two semi-automatic weapons, two shotguns, and a lever-action firearm (five firearms in total).
In contrast, President Donald Trump has repeatedly told mourning Americans in the wake of shootings that stricter gun control would make the country more unsafe, not less.