Yesterday it emerged that there have been two deaths in Christchurch in the past fortnight through suspected use of synthetics, and 19 people hospitalised by what emergency doctors called a "particularly bad batch" of synthetics.
Around 45 deaths in the year to June have been attributed to synthetics use.
Clark said he would not be revisiting his decision earlier this year not to hold an separate review into synthetics, saying it would be covered by the broader Inquiry into Mental Health and Addiction. There was also work underway between Health, Police, Customs and Corrections.
"We're having a good look at that area just because of the public concern that's been raised by reports that over the last year and a half there have been a number of deaths.
"There are no silver bullets but there are things that we are looking to do with synthetics because it's becoming clear just how dangerous they are," Clark said.
The Green Party warned the Government not to pursue a costly war on synthetic drugs that was destined to fail.
"David Clark's call to reclassify two of the synthetic compounds as Class A drugs puts our country on the wrong path. This a critical moment for drug policy direction. We can choose to carry on with a failed war on drugs, or take a more sensible route and look at the causes and health impacts of addiction and treat those instead," said Chloe Swarbrick, Greens' spokeswoman on drug law reform.
Prime Minister Jacinda Ardern downplayed the parties' differences of opinion on the issue.
"I think we're all ultimately on the same page," she told reporters today.
"We want to reduce the harm that's being done by synthetic cannabis. We are taking a health-based approach. We do want to make sure there are the community services available," she said.
National leader Simon Bridges said while it was good the Government was moving to
reclassify some compounds in synthetics, it should go further.
"The drug manufacturers will simply change the recipes. We would say to the Government go further, take more advice and be wider on this Class A issue," Bridges said.