Survivors, family of victims and New Zealand Prime Minister Jacinda Ardern were among hundreds who showed up for the memorial service which was held marking two years since a gunman murdered 51 people in attacks on two mosques in Christchurch, New Zealand.

Ardern said there is still an impact on the community from the horrific attack, "but it is never too early or too late for the legacy to be a more inclusive nation."

During the emotional service, she noted that the country had a "duty" to support the Muslim community. 

Ardern, who received wide praise for the support shown to survivors and the families of the victims of the shooting and her swift move to tighten weapon control in in the country, said words "despite their healing power" would never change what happened.

A man who was shot nine times in the face, arms, and legs, Temel Atacocugu, wept uncontrollably as he recalled waiting to be treated alongside a father of a three-year-old, Mucaad Ibrahim, who learned that his toddler has just passed away.

"Suddenly, my pain seemed insignificant," said Atacocugu, noting that it was a miracle he was alive.

"I have since had seven major surgeries and there are more to come. I will carry lots of shrapnels in my body for the rest of my life. Every time I have an X-ray it lights up like a Christmas tree."

The gunman, self-proclaimed white supremacist Brenton Tarrant, was arrested minutes after the attacks on the Al Noor mosque and Linwood Islamic Centre.

He pleaded guilty to 51 charges of murder, 40 of attempted murder and one of terrorism, and was sentenced last year to life imprisonment without parole, the first time a whole life term has been handed down in New Zealand.

Notably, Last week, police arrested a 27-year-old man in Christchurch and charged him with threatening to kill following online threats to the same two mosques.