New Zealand has bought back nearly 20,000 firearms after banning assault weapons. Here's what's next.

One crackdown on assault weapons wasn't enough for New Zealand.

After a March mass shooting left 51 people dead at two mosques in Christchurch, New Zealand, Prime Minister Jacinda Ardern moved the country to ban semiautomatic rifles and institute mandatory buybacks in less than a week. Thousands of people have so far turned in their weapons, and Ardern is now moving to tighten gun laws even further, Reuters reports.

In a bill introduced Friday to Parliament, Ardern proposes creating a registry for every firearm legally purchased and owned in New Zealand. The bill also would require gun licenses be renewed every 5 years instead of the current 10, and enact more stringent rules for how people and businesses can maintain those licenses.

Meanwhile, the country is halfway through an amnesty period during which gun owners can be paid to turn in legally purchased yet newly prohibited weapons and ammunition. They can also anonymously turn in weapons for no compensation, per NPR. The program started in June and runs through Dec. 20, after which stiff penalties for owning the banned items will go into effect. So far, 12,621 people had turned in 19,837 firearms and 73,949 parts, the New Zealand Herald reports.

The March shootings exceeded New Zealand's homicide count for 2019 in just a matter of hours, prompting Ardern and Parliament to enact a ban on AR-15s and all similar assault rifles in just a few days. 2020 Democratic presidential candidate Beto O'Rourke has called for a similar assault weapons ban and buyback after a mass shooting killed 22 people in his El Paso, Texas, hometown.