Ardern said that New Zealand was in shock and informed Khan of immediate actions taken after the attack including the banning of all military style semi and automatic guns and assault rifles.
"All semi-automatic weapons used during the terrorist attack on Friday 15 March will be banned".
Ardern said the sales ban was effective immediately to prevent stockpiling and would be followed by a complete ban on the weapons after new laws were rushed through.
The woman is believed to be connected to the shootings but she's still alive, said Det. The gunman used semi-automatic AR-15 rifles, with large magazines, and shotguns.
The New Zealand Police reports approximately 1.2 million guns in the country, and Arden estimated that buying them back, as the Cabinet has directed, could cost the country as much as $100 million to $200 million.
The government said the police and military would be exempt as would businesses carrying out professional pest control.
New Zealand police have admitted a mistake meant they charged the man arrested over the Christchurch mosque shootings with killing someone who is still alive.
After Australia implemented a similar ban, the country destroyed more than a million weapons, and additional gun buybacks and amnesties have been conducted since.
Ms Lee says these handguns are much easier to hide than their longarm equivalents, are often used in drive-by shootings, and are the most commonly used gun in United States mass shootings.
"This will not be popular among some of our members", security spokesperson Miles Anderson said.
Addressing other world leaders in an interview this week, Ardern said white nationalism must be confronted "where it exists", and nations must make sure they "never create an environment where it can flourish".
But Ardern's dignity and steel has now proven her detractors wrong, and shown that running her country is a challenge she's more than qualified to handle.
Farming lobby group Federated Farmers said it backed the decision.
"So I'm quite happy to hand mine over".
Nada Tawfeek, who buried her father-in-law killed in the attacks, Hussein Moustafa, on Thursday, welcomed the ban. "I can assure people that there is no point in applying for such a permit", she said.
The first victims were buried on Wednesday and burials continued on Thursday, with the funeral of a school boy.
If the mosque is not ready, the Friday prayers will be held across the road in the spacious Hagley Park. The call to prayer will telecast nationally.
Police Commissioner Mike Bush said investigators were trying to conclude their work at the two mosques.
Both mosques attacked, the Al Noor and nearby Linwood mosque, plan to be reopened.
Most victims were migrants or refugees from countries such as Pakistan, India, Malaysia, Indonesia, Turkey, Somalia, Afghanistan and Bangladesh.
Brandon Tarrant, 28, is accused of one count of murder and is expected to face more charges.
Out of a total of 50 people injured, 29 are still hospitalized, of which nine remain in serious condition, including a 4-year-old girl who was transferred to Auckland on the North Island earlier this week.