Wheeler's jawboning of the currency comes after Finance Minister Bill English yesterday reiterated his view the kiwi was "unsustainably high" telling BusinessDesk on the sidelines of a Trans-Tasman Business Circle lunch in Wellington that "almost anyone who has looked at it comes to the conclusion it's somewhere 10 to 15 percent overvalued."
ASB's Kelleher said a sustained fall will need a stronger US dollar, which may get a boost if figures next week support growth prospects in the world's biggest economy.
New Zealand government figures today showed a trade surplus of $247 million in June, from a revised $270 million in May and $371 million a year earlier. The annual trade balance turned to a surplus of $1.2 billion from a deficit of $819 million a year earlier.
The figures beat expectations for a monthly surplus of $150 million and an annual surplus of $1.15 billion in a Reuters poll of economists.
Global demand for New Zealand dairy products has underpinned the country's exports over the past 18 months, though prices have dropped this year amid increased supply.
Fonterra Cooperative Group's board will review the milk price it expects to pay farmers next week, and economists are forecasting a lower payout.
ASB's Kelleher said there's a downward revision in the price that would be another negative for the kiwi dollar.
The local currency dropped to 87.07 yen at 5pm in Wellington from 88.03 yen yesterday, and declined to 90.84 Australian cents from 92 cents. It fell to 63.77 euro cents from 64.47 cents yesterday, decreased to 50.38 British pence from 50.84 pence.