Matt Kean has told a budget estimates hearing it was "a matter of public record" that he does not believe the government is doing enough to protect koalas but would not provide detail on what the new plan would entail.

The plan would "focus on things like" protecting habitat and monitoring population and details would be released "as soon as possible", he said on Tuesday.

Asked whether any of the money for the plan had come from a 25 per cent budget cut to NSW's Saving our Species program, Mr Kean said it was "new money" that was "separate and in addition" to the existing program.

Mr Kean acknowledged it was not acceptable only four of the 26 recommendations from a 2018 strategy had been implemented.

Opposition environment spokeswoman Penny Sharpe said the recommendations that had been implemented essentially amounted to "looking at koalas, looking at where their trees are and saving their dead genetic material".

Mr Kean agreed not enough was being done to protect koalas under threat and reiterated the government "will be announcing a comprehensive plan developed with some of the best scientists in the country".

Work on a new code for private native forestry is underway and Mr Kean said he will not agree to the removal of protections for core koala habitat, saying any attempt at removing the protections would be "a line in the sand" for him.

There were "some major sticking points" in negotiations over the remake of the private native forestry codes and logging "was one of them", he said.

He refused to "play hypotheticals" about who was on the other side of his "line in the sand" but said as long as he is the environment minister he will "stand up and argue for koalas very strongly".

Australian Associated Press