The government is announcing a new declaration for youth offenders with harsher penalties.
The new Young Serious Offender (YSO) declaration can be applied to teenagers between 14 and 17 who have committed two offences punishable by 10 years of imprisonment.
So-called YSOs may be sent to a military-style boot camp which is entering its pilot phase.
The government says they aim to reduce youth reoffending by 15 percent.
Meanwhile an additional 21 police officers will be redeployed in Auckland City, bringing the total number of beat police in the central city to 51 by the end of July.
It is the start of a staged two-year roll out, which will see 63 additional staff deployed in new Community Beat Teams across Auckland's three policing districts, with 17 in Wellington and 10 in Christchurch.
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The Prime Minister also said gang members should expect harsher penalties later this year.
Luxon said gang membership will become an aggravating factor in sentencing and gang patches will be banned in public.
He says the new rules will be passed in August and be in effect starting in November.
Luxon said three strikes legislation will be reinstated in November for serious crimes including sexual assault.