The Ministry for Primary Industries is appealing the High Court's decision that found in favour of kiwifruit growers over the introduction of the devastating bacterial disease Psa.
The Crown appeal seeks to clarify the scope for government regulators to be sued in negligence, MPI said.
MPI said the High Court's finding traverses events dating back 12 years, pre-dating the establishment of the Ministry.
"New Zealand enjoys a high level of freedom from the most damaging pests and diseases as a result of the diligent actions of MPI officers, importers and others," MPI said.
"No biosecurity system in the world can prevent every pest incursion from happening, which is why our ability to manage risk offshore and respond to incursions if they occur are critical parts of the biosecurity system," it said.