New Zealand posted a merchandise trade deficit of NZ$1.143 billion in September, Statistics New Zealand said on Thursday - representing 30 percent of exports.
The headline figure missed expectations for a shortfall of NZ$900 million following the NZ$1.179 billion deficit in August.
Exports were up NZ$313 million or 9.0 percent on year to NZ$3.78 billion, missing forecasts for NZ$3.90 billion but up from NZ$3.69 billion in the previous month.
Milk powder, butter, and cheese exports climbed NZ$175 million in September to NZ$791 million, up 28 percent on year.
Milk fats including butter led the rise in dairy-related sales, up NZ$62 million (43 percent) to NZ$207 million, even though volumes fell.
Milk powder (up NZ$58 million), and milk and cream (up NZ$44 million), also contributed to the rise. The average unit price of butter was NZ$8,280 a ton in September compared with less than NZ$5,000 a ton a year earlier.
"The increases in both butter and milk powder were price-driven," international statistics manager Tehseen Islam said. "Milk and cream were mainly volume-driven, especially to China, though prices were up, too."
Almost 80 percent of milk and cream were exported to China.
Exports of food preparations, including infant formula, were up by NZ$58 million (104 percent) in September. Over half of this commodity was exported to China.
Imports advanced an annual 1.4 percent or NZ$67 million to NZ$4.9 billion - roughly in line with expectations for NZ$4.88 billion after showing NZ$4.92 billion a month earlier.
Mechanical machinery and equipment jumped NZ$116 million (19 percent), while food residues, wastes, and fodder surged NZ$47 million (118 percent).
Automotive diesel climbed NZ$46 million, while vehicles, parts, and accessories rose NZ$41 million.
Aircraft and parts fell NZ$242 million and crude oil fell NZ$107 million.