One of the shooters, who live streamed the attack was Brenton Tarrant, 28, from Grafton New South Wales.
“I am deeply saddened by the appalling event in Christchurch today. Prince Phillip and I send our condolences to the families and friends of those who have lost their lives,” the statement read.
“I also pay tribute to the emergency services and volunteers who are providing support to those who have been injured. At this time, my thoughts and prayers are with all New Zealanders.”
The Duke and Duchess of Cambridge and the Duke and Duchess of Sussex have also sent their condolences in a joint statement.
"Our hearts go out to the families and friends of those who lost their lives in the devastating attack in Christchurch. We have been fortunate to spend time in Christchurch and have felt the warm, open-hearted and generous spirit that is core to its remarkable people," the message read.
"No person should ever have to fear attending a sacred place of worship. This senseless attack is an affront to the people of Christchurch and New Zealand, and the broader Muslim community. It is a horrifying assault on a way of life that embodies decency, community and friendship.
"We send our thoughts and prayers to everyone in New Zealand today. Kia Kaha."
Meanwhile, Prime Minister Jacinda Ardern described the incident as one of New Zealand's "darkest days".
"Clearly what has happened here is an extraordinary and unprecedented act of violence," she said.
"For now, my thoughts, and I'm sure the thoughts of all New Zealanders, are with those who have been affected, and also with their families."