New Zealand PM Jacinda Ardern has said she will announce detailed gun law reforms within days, after an attack on two mosques left 50 people dead.
Ms Ardern said her cabinet had backed gun law changes "in principle".
Australian Brenton Tarrant, 28, a self-described white supremacist, has been charged with murder.
Police say the killer used military-style assault weapons modified to make them more deadly - which is not illegal under current legislation.
What has the cabinet agreed?
The prime minister gave no details at her press conference on Monday but said they would made clear soon.
"This ultimately means that within 10 days of this horrific act of terrorism, we will have announced reforms which will, I believe, make our community safer," she said.
Ms Ardern was appearing alongside her coalition partner and Deputy PM Winston Peters, who has previously opposed changes to gun laws.
Mr Peters said he fully supported the prime minister on the issue, adding: "The reality is that after 1pm on Friday, our world changed forever and so will our laws."
Ms Ardern said: "We have made a decision as a cabinet. We are unified."
She also announced that an inquiry would look into the lead-up to the attacks, and what might have been done differently.
What do we know about the guns used?
At the weekend, Ms Ardern said the suspect had a gun licence, obtained in November 2017, and owned five guns.
Earlier on Monday, gun retailer Gun City said it had sold four weapons to the alleged gunman online, but it did not sell him the high-powered weapon used in the mosque shootings.
CEO David Tipple told a news conference in Christchurch it had only sold him A-category weapons.
Under New Zealand's gun laws, A-category weapons can be semi-automatic but limited to seven shots. Video footage of the attacks appeared to show the gunman's weapon had a magazine with a larger capacity, which is also available legally.
There are an estimated 1.5 million privately owned firearms in the country.
Since the attack there have been calls for semi-automatic weapons to be banned.
Previous attempts to tighten gun laws have failed due to a strong gun lobby and a culture of hunting.
New Zealand's gun laws
- The minimum legal age to own a gun in New Zealand is 16, or 18 for military-style semi-automatic weapons. Anyone over those ages who is considered by police to be "fit and proper" can possess a firearm
- All gun-owners must have a licence, but most individual weapons do not have to be registered. New Zealand is one of the few countries where this is the case
- Applicants for a firearms licence must pass a background check of criminal and medical records
- Once a licence has been issued, gun owners can buy as many weapons as they want
What do we know about the footage of the attack?
Footage of the killings was live-streamed by the attacker. On Sunday police said it was now classified as an objectionable publication and therefore it was an offence to distribute or possess the material.
An 18-year-old appeared in court on Monday, charged with distributing the live-stream. The teenager was also charged with publishing a photograph of the mosque with the message "target acquired" and faces a maximum of 14 years in prison for each charge, according to the prosecution.
Facebook said it had removed 1.5 million videos of the attack around the world in the first 24 hours.
Emotion still raw
By Jay Savage, BBC News, Christchurch
Many returned to work and school on Monday, but little about it felt ordinary. If anything, the signs of the city's emotions became more visible.
Flowers left at the main tribute site swelled, easily doubling what was there a day earlier.
Outside Al Noor mosque, hundreds of people attended an afternoon vigil. It featured a thundering haka, performed by dozens of schoolchildren. Other students stood together singing softly or linking arms in silence. A few cried openly.
The importance of coming together was the main topic of conversation.
What is the latest on the victims?
Nine people remain in hospital in a critical condition.
Frustration is building among relatives over the release of the bodies of the dead for burial.
The first release was approved on Sunday but the family say another relative was killed and they want them released together. No burials will take place on Monday.
Islamic tradition calls for the cleansing and burial of bodies as soon as possible after death.
And on the suspected gunman?
Brenton Tarrant on Monday fired his state-appointed lawyer, Richard Peters.
Mr Peters says the defendant has indicated he "wants to be self-represented in this case".
The lawyer added: "The way he presented was rational and someone who was not suffering any mental disability. He seemed to understand what was going on."
Australian police raided two homes near Sydney on Monday as part of the inquiry.
Australian media reported that one of the homes belongs to Brenton Tarrant's sister. The family is co-operating with the authorities.
An uncle of Brenton Tarrant said: "We are so sorry for the families over there, for the dead and injured."
New Zealand police confirmed on Monday they believed there was only one attacker, but added that this did not rule out others might have provided support.