"This is the next frontier."
Ardern said there were tests in place to make sure the right people were being targeted, including listening to experts and police.
On the $30,000 threshold, Ardern said "there has been a range of views".
The Government is keeping an open mind and police would like to see it lower, she said.
Justice Minister Kiri Allan said the change was "about ensuring crime doesn't pay and that there are major consequences for criminal and gang activity".
She said that under the current regime, "organised criminals structure their affairs to avoid their illicit assets being restrained and forfeited".
"This is done by creating distance between themselves and the assets by putting property into associates' names," she said.
Allan's message to people hiding assets is "time is up".
When asked about why the Government was focusing on seizures just now, Allan said they've been working on it for some time.
It's technical and has required a lot of engagement, she said.
Allan said "a number of cases" have come up through the courts showing some criminals are using KiwiSaver to stow away misbegotten gains.
She didn't know specifically how many cases there have been, but believed it was a "significant number".
Police Minister Chris Hipkins said the problem was widespread.
"Police's experience with criminal proceeds investigations tells us that use of intermediaries, third parties, relatives or friends are a feature of many cases now investigated," Hipkins said.
"The steps taken today continue the Government's multi-faceted approach to tackling the harm caused by gangs and other organised criminal groups.
"This is the next step in the Government's work to curb crime and make our communities safer. It will mean that not only do we have more frontline Police than ever before, they also have greater powers to hit gangs where it hurts," he said.
The law change will grant police new powers to target the associates of organised criminal groups and restrain their property, when it is clear their legitimate finances would've been unlikely to have enabled them to acquire the assets.
It will also create a new court order that will mean criminals based overseas who have assets in New Zealand will face losing those assets, unless they can provide proof within two months that they obtained their property legally.
The law change will also allow the Government to seize the funds in KiwiSaver funds, eliminating the potential for criminals to hide illegal funds in their KiwiSaver.
The Government was concerned criminal groups had been structuring their activities to make it appear that property acquired through the proceeds of crime was not linked to them, but was owned via an associate.
Criminals could register things like property and vehicles to the names of associates and family members to avoid linking them to criminal activity.
National has already come out against the changes.
Responding to reports the bill was set to be introduced, the party's police spokesman Mark Mitchell told Newstalk ZB that while he supported seizing gang assets, the bill missed the bigger issue.
"They are not going to make any tangible impact right now on the amount of gang violence and gun violence that we're currently experiencing," Mitchell said.
The Act Party called the bill a "U-turn".
The party's justice spokeswoman Nicole McKee said Labour had "finally accepted the logic Act has been promoting for years, if you want to tackle the gangs you need to hit them where they hurt – their wallets".
"If you take the profit out of gangs then you take away the incentive. If there's money to be made they'll find a way around law enforcement. If there's no money to be made they'll give up," McKee said.
'Serious allegations have been raised'
Ardrern said she disagreed nothing is being done about all the people in emergency hotel housing around the country, responding to a story on Visions for Helping Hands, which was featured on TVNZ's Sunday programme.
Ardern said the housing minister would respond to specific allegations.
Ardern was asked: "Yes or no, does there need to be an independent investigation?"
Ardern responded: "Some serious allegations have been raised...and they were taken to the police".
"That is where you would expect those issues to be followed through."
Ardern said the Ministry of Housing and Urban Development has brought in a QC to take a look at that (complaint) process and "make sure it is operating as we would expect".
"In the past five years, we've seen increasing demand for emergency housing."
Ardern said 200 have been built, and 300 were under construction.
"The question is what do you do in the meantime.
"Rotorua has had some particular challenges. We haven't always got it right."
Covid-19 settings
When asked when the next Covid-19 settings decisions will be made, Ardern said these issues are "under active consideration".
"We'll be getting into details of that next week."
Ardern was also asked about test-to-release Covid-19 modelling, and bringing isolation down to five days, but relying on two negative RAT tests.
"One of the things we routinely look at is the isolation periods. These are all things that are under consideration by Cabinet."
"When we review, we always look at the periods of isolation."
Kiwis in Ukraine
When asked if the Government was aware of how many New Zealanders were currently in Ukraine, Ardern replied "in short, no."
Last week, Ardern heard there were six people listed as being in Ukraine with SafeTravel.
"There's an expectation" no one with NZDF would be in Ukraine.
Ardern is not aware of anyone resigning from the NZDF to fight in Ukraine.
