Diplomats are battling to find consensus on global drug policy at the United Nations this week.

The special assembly follows growing concerns over the so-called "war on drugs", which the UN says hasn't worked.

Ross Bell from the New Zealand Drug Foundation said there are two camps of countries - hardliners like Russia, China, and Iran, which are pushing for a prohibitionist approach and the death penalty.

LISTEN ABOVE: Ross Bell speaks to Rachel Smalley

He told Rachel Smalley New Zealand is in the second camp - advocating for a public health approach, which has been implemented successfully in Portugal through the decriminalisation of drugs.

"And swapped that criminal approach with a health approach, so at the time time as changing the law, they invested in education and prevention and treatment. What they've seen is that youth drug use has gone down, they've seen adult use gone down, seen overdose deaths go down."

Bell said Associate Health Minister Peter Dunne is showing signs of backing a more progressive approach.

"His new drug policy says in its very first sentence that New Zealand's alcohol and drug problem is first and foremost a health issue, and he goes on to say we need compassion, proportion and innovation, so he is fundamentally calling for change."