"Australia has the worst mammal extinction rate in the world and today in NSW, on Threatened Species Day, we say no more," Environment Minister Matt Kean said.

"Globally, one million species face extinction over the coming decades and, as international biodiversity negotiations continue, everyone needs to aim high."

Mr Kean is comparing the target of zero extinctions to his net zero emissions goal.

"But our plan isn't just about targets - it's also about action," he said in a statement on Tuesday.

Mr Kean has declared 221 sites in NSW national parks to be "assets of intergenerational significance".

That label was first given to a forest of rare Wollemi pines in January.

The designation means the government can take extra measures to protect the sites from bushfires, protecting them for future generations.

The sites are home to species at risk from feral animals, bushfire and climate change.

The protected sites span 110 national parks and more than 300,000 hectares, of almost four per cent of the entire National Parks Estate.

The species targeted under the plan include the brush-tailed rock-wallaby, which is found at seven of the protected sites.

There are less than 10 of the wallabies at the Warrumbungles in the state's west.

Fifteen sites popular with koalas are also getting new protection.

In total, 27 animal species, including 13 mammals, four birds, seven frogs and three reptiles, will be protected as well as 66 plant species, including the Wollemi pine.

Australian Associated Press