Exports for January topped $3.9billion, but were overshadowed by $4.19billion of imports. Oil imports accounted for almost $250million, up about $146million on a year ago.
Westpac economist Sarah Drought said the January deterioration of the trade balance widened the deficit to $285million.
''However, a significant contributor to the surprisingly large deficit was a spike higher in the volume of oil imports, which is likely to reverse next month.
''Excluding oil imports and exports, the monthly deficit was a more moderate $36million,'' Ms Drought said.
ASB senior rural economist Nathan Penny said the country's trade balance was weaker than expected for January. The ASB forecast expected a small $50million surplus, not the $285million deficit.
''Most of the weakness versus expectations came via stronger-than-expected import values,'' Mr Penny said.
The import strength was broad-based, and in line with similarly robust indicators of domestic demand, ''although some of the strength may owe to timing and may partially unwind next month'', he cautioned.
Vehicles, parts and accessories import values were particularly strong, jumping 28.3% in annual terms.
Mr Penny said the export values were more in line with expectations for the month, lifting 1.4% in seasonally adjusted terms, but the stronger-than-expected meat export values offset weaker-than-expected dairy export values.
''For the month, dairy export values were largely flat, with a 3.5% lift in prices offset by a decline in export volumes,'' he said.
On the dairy export price front, Mr Penny anticipated further increases based on strong dairy auction results and a 10% export price lift this month.
''We expect that the balance of this price lift is likely to come through in the February trade figures,'' he said.
Ms Drought said while oil imports boosted the aggregate figures in the month, strength was relatively broad based.
With the New Zealand dollar 9.2% higher over the year, this implies strong growth in import volumes, consistent with an economy ''running at a decent clip''.
While vehicle imports remain a standout, growth in capital imports has picked up after a lull last year, potentially indicating an improvement in business investment ahead, she said.
