Ardern also said that Trump conveyed "his absolutely horror and disgust" about the attack. "At this point in time we should never make assumptions", he said.
Nour Tavis said one of his friends lost his wife during the terror attack, in which 49 people were killed at two separate shootings, after she turned back to look for him. The attacks seem to be a carefully planned and the authorities detained four people and defused explosive devices that are said to have belonged to the attackers.
Two others remain in police custody, with the fourth person arrested deemed not to have been involved in the attacks.
Mia Garlick, of Facebook in New Zealand, said, "We will continue working directly with New Zealand Police as their response and investigation continues".
Media reported that a gunman opened fire inside a mosque in Christchurch's Hagley Park district.
Indonesian Woman Suspected in Assassination of Kim Jong Un's Half-Brother Released
They were the only suspects in custody after four North Korean suspects fled the country on the morning Kim was killed. While Indonesia lobbied for Aisyah's release, Vietnam has been more reluctant to get involved in a red family feud.
New Zealanders are trying to come to grips with the worst massacre in their nation outside of wartime in more than 200 years.
He tweeted: "Our hearts go out to the people of New Zealand following the news of this awful act in Christchurch". He issued a tweet Friday, offering his sympathy and best wishes to the country after 49 people were killed and dozens were injured in what's being considered a terrorist attack. "Just heard news of the devastating reports from New Zealand Christchurch", he wrote.
Mohan Ibrahim told the New Zealand Herald: "At first we thought it was an electric shock but then all these people started running".
She pronounced it "one of New Zealand's darkest days".
The attacks targeted the Masjid al Noor mosque, where 41 people died, and a second, smaller mosque in the suburb of Linwood, where seven more died.
"They were on the bus, which was just pulling up to the mosque when the shooting begun", Mario Villavarayen, strength and conditioning coach of the Bangladesh cricket team, told Reuters in a message.
The Linwood Avenue mosque is one of two which have subject to a shooting, with another taking place at a mosque on Deans Avenue.