New Zealand will ban all types of semi-automatic weapons and assault rifles following the Christchurch attacks, Prime Minister Jacinda Ardern has said.
The announcement comes less than a week after 50 people were killed at two mosques, allegedly by a lone gunman.
Ms Ardern said she expected new legislation to be in place by 11 April, saying: "Our history changed forever. Now, our laws will too."
All of the dead have now been formally identified, police have confirmed.
Australian Brenton Tarrant, a self-proclaimed white supremacist, has been charged with one murder and was expected to face further charges.
However, police said on Thursday that the person he was formally accused of killing had been wrongly declared dead.
They said they had apologised to the woman and her family, and that the charge sheet would be updated when the suspect appeared in court on 5 April.
What will change and how soon?
"Six days after this attack, we are announcing a ban on all military style semi-automatics (MSSA) and assault rifles in New Zealand," Ms Ardern said in a news conference.
"Related parts used to convert these guns into MSSAs are also being banned, along with all high-capacity magazines."
An amnesty has been imposed so the owners of affected weapons can hand them in, and a buy-back scheme will follow.
Ms Ardern said the buy-back could cost up to NZ$200m ($138m; £104m), but "that is the price that we must pay to ensure the safety of our communities".
The prime minister has called the Christchurch attacker a terrorist and said she will not utter his name.
The lone gunman, armed with semi-automatic rifles including an AR-15, is believed to have modified his weapons with high-capacity magazines - the part of the gun which stores ammunition - so they could hold more bullets.
Ms Ardern said measures had also been introduced to prevent gun stockpiling before the law changes.