The Ministry for Primary Industries is improving biosecurity systems at the border after a report highlighted shortcomings.
The Ministry (MPI) commissioned consultancy firm Grant Thornton to review its cargo systems in 2019.
The Ministry said this was used as an internal resource andit had now released the findings publicly.
The report said while New Zealand's biosecurity system has previously operated effectively, it was under threat. It said this was evidenced by recent major events such as Mycoplasma bovis, Psa, and fruit fly which had billion-dollar effects on the economy.
"MPI is doing its best within current constraints, however the pressing need to clear inbound cargo dominates most activities."
"In this regard, the impact of the BMSB (brown marmorated stink bug) season on MPI cannot be overstated. Both New Zealand and Australia are struggling to prevent the establishment of this devastating pest which can infect and destroy over 300 types of host plants."
The report said pressures on MPI from the above issues, combined with increasing biosecurity threats and risks and increasing cargo volumes, appeared to have made MPI too focused on tactical or immediate outcomes.
It warned this approach may not be adequate enough in the long term.
"The observations over the course of this review raise uncertainty as to whether MPI are building capability quickly enough or that the present approach to managing biosecurity is sustainable."
The report made 68 recommendations, including changes to cargo clearance processes, better allocation of resources, more engagement with industry and a stronger focus on automation and innovation.
MPI biosecurity spokesperson Steve Gilbert said it was already implementing most of the recommendations and was tracking progress. Cargo clearance times were reducing, he said.
Gilbert said over the past year, the number of brown marmorated stinkbugs detected at the border had dropped significantly thanks to stricter import requirements for high-risk cargo from countries with established populations.
He said a review of the Biosecurity Act was also under way and that would strengthen legislative support for biosecurity activities.
