The trade accounts improved last month, with exports exceeding imports by $486 million.
It still left the balance for the year at $1.2 billion in deficit, as imports outstripped exports by 2.6 per cent.
That was advance on annual deficits of $1.4 billion in November and October, but a $2 billion deterioration from the $800 million trade surplus recorded in 2011.
Dairy export volumes improved last month for the second month in a row, following three months of decline, to be up 14 per cent on December 2011.
"However, if the dry conditions in the North Island persist, poor grass growing conditions and high feed costs could limit this season's production performance," ASB economist Jane Turner said.