WELLINGTON - A new gun law following the Christchurch shootings on March 15 has passed its first reading in New Zealand's parliament on Tuesday.

New Zealand's Prime Minister Jacinda Ardern announced the morning after the shootings that gun laws must change.

New Zealand's Police Minister Stuart Nash said the attacks in Christchurch exposed the considerable weaknesses in New Zealand's current firearms law.

The most critical weakness in the firearms law is that too many people have legal access to too many semi-automatic firearms capable of causing significant harm, he said.

"We are driven by one objective. We are driven by the need to ensure public safety is as strong as it can be. We are also driven by the memory of fifty men, women and children who were taken from their loved ones on March 15. Their memory is our responsibility. We don't ever want to see an attack like this in our country again. We are compelled to act quickly," said Nash.

New Zealand's current firearms legislation came into force 35 years ago. It dates from the 1980s, a time when the country was more isolated from the rest of the world, he said. There were strong import controls and no internet market place or social media.

"Since this time, firearms technology has shifted, the weapons market has become global and there are a significant online community and trading environment. To bring the firearms legislation more up-to-date and substantially reduce loopholes and risk, major change is needed. This Bill takes the first steps to modernize the Act," said Nash.

The new gun law seeks to essentially ban all semi-automatic weapons. However, it is important to reiterate that the legislation is not directed at law-abiding firearms owners who have legitimate uses for their guns.

"Our actions are instead directed at making sure March 15 never happens again. Semi-automatic firearms which are commonly used for hunting, pest control, stock management on farms, and duck shooting will not be affected," said Nash.

Meanwhile, the government will implement a buyback scheme for the newly banned firearms which are surrendered.

The government is currently working on the details of the buyback scheme and will make announcements shortly.

Arden said, "The cost of the buyback scheme would cost around 100 to 200 million New Zealand dollars."

"We recognize it is a substantial amount of money but we are committed to doing this. We will find the money to do this because it's about making New Zealanders safe. We will remove these guns from our communities," said Nash.