• New Zealand Prime Minister Jacinda Ardern on Thursday announced a ban on all "military-style semiautomatic weapons" and assault rifles.
  • "In short, every semiautomatic weapon used in the terrorist attack on Friday will be banned in this country," Ardern said.
  • The program will include a "buyback scheme" for banned weapons that officials estimate will cost between "$100 million and $200 million," Ardern added.
  • The announcement comes less than a week after 50 people were killed in shootings at two mosques in Christchurch.

New Zealand Prime Minister Jacinda Ardern announced a ban on all "military-style semiautomatic weapons" and assault rifles, at a press conference on Thursday local time.

"In short, every semiautomatic weapon used in the terrorist attack on Friday will be banned in this country," Ardern said.

The announcement comes less than a week after a shooting at two mosques in Christchurch left 50 dead and more than 40 wounded.

"Today I am announcing that New Zealand will ban all military-style semiautomatic weapons," she said. "We will also ban all assault rifles. We will ban all high-capacity magazines. We will ban all parts with the ability to convert semiautomatic or any other type of firearm into a military-style semi-automatic weapon. We will ban parts that cause a firearm to generate semiautomatic, automatic, or close to automatic gunfire."

Read more: What we know about the guns used in the Christchurch mosque attacks, and how New Zealand's gun laws could change after the massacre

The new law would immediately ban the sale of the guns, and it will be followed up with legislation to define the proposed "buyback scheme" for banned weapons and other gun law issues. Officials estimate the buyback will cost between "$100 million and $200 million," Ardern said.

"Today, the Government has made immediate changes to classifications in the Arms Act which will mean some firearms are going to be reclassified as military-style semiautomatic firearms," Police Commissioner Mike Bush said in a press conference that followed Ardern's.

"At 3 p.m. [local time] today, changes have been by an Order in Council under section 74A(c) of the Arms Act came into force adding two more groups of semiautomatics under the MSSA definition."

2 types of guns will not be affected by the ban, according to a government fact sheet obtained by The Guardian:

  • Semiautomatic .22-caliber rimfire firearms with a magazine which holds no more than ten rounds and semiautomatic and pump-action shotguns with a nondetachable tubular magazine which holds no more than five rounds.

Other guns will be immediately affected:

  • Semiautomatic firearms and shotguns "capable of being used with a detachable magazine, which holds more than five cartridges" are part of the ban.

Read more: 10 strategies proposed to stop shootings in America, and how likely they are to work

If citizens have the improper license to own a military-style semiautomatic weapon, or MSSA, there will be a program to surrender their weapons to the police along with an online form and phone number to arrange for surrender. There will be an amnesty period for people to hand over their weapons, Bush added.

During her press conference, Ardern said that gun owners had expressed support for changes to the country's gun laws.

"I absolutely believe there will be a common view amongst New Zealanders, those who use guns for legitimate purposes, and those who have never touched one, that the time for the mass and easy availability of these weapons must end," she said. "And today they will."

This article was written by Sarah Gray from Business Insider and was legally licensed through the NewsCred publisher network. Please direct all licensing questions to legal@newscred.com.