The government is announcing its decision about whether to eradicate or contain the cattle disease, Mycoplasma bovis.
The disease was discovered in July last year and since then 41 farms have been confirmed as infected. That has since dropped to 37 farms, with more than 11,000 cattle slaughtered.
The bacterium causes illness in cattle, including udder infections, abortion, pneumonia and arthritis.
It does not affect humans and MPI said it presents no food safety risk.
Prime Minister Jacinda Ardern is announcing the government's decision at Federated Farmers' headquarters in Wellington.
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