Personal responsibility is critical to staying alive, Prime Minister Bill English said when asked about how best to tackle synthetic cannabis which looks to have claimed seven lives in Auckland this month.
Combating the death toll, and the possibility it could rise with at least 20 people also hospitalised after using the drug, is a matter for police according to the prime minister.
Mr English said he's sought advice on feasible approaches to controlling the drug crisis that is developing on Auckland's streets but says it's up to police and users to take action.
"The most important thing here is that people do not take these illegal substances that can kill them," he said on Monday.
"That sense of personal responsibility is pretty critical to staying alive."
Mr English said synthetic cannabis was not a harmless recreational drug, but a potentially lethal substance because nobody knows what's in them.
Solutions to the problem include active policing and potential users exercising "self-preservation", he said.
Chief coroner Deborah Marshall and police issued urgent warnings on Friday for people to steer clear of the drugs.
Judge Marshall said Coronial Services had been notified of at least seven deaths where the person is believed to have used synthetic cannabis or were found to have the drug on them when they died, while a significant number of non-fatal cases have also been recorded by St John.
Associate health minister Peter Dunne told NZ Newswire on Friday that the deaths were "eminently foreseeable" because of legislation brought in by the Government in May 2014.
Parliament banned all legal highs until they could pass a testing regime, but bans on animal testing means that rule has become unworkable.
Mr English admitted the ban on animal testing had made it "reasonably challenging" to get the drugs tested.
"At the time there was indications that there may be [other means of testing] but it wouldn't be easy," he said.
Mr Dunne is seeking updated advice from officials on what alternative testing options may now be available.