Westpac warns trade with China is a key risk area for the New Zealand economy

The bank has revised down its milk forecast for the coming season to seven-dollars-50 - down from 7.80 - in its latest overview.

Its chief economist says the key problem is weak activity in China, which was hoped to have a growth boost after its lockdowns.

Kelly Eckhold says instead, Chinese economic growth expectations have been pecked back.

He says that has been reflected in weaker commodity prices for products like dairy, meat and logs - making for a worse year than hoped for the agricultural sector.