The Reserve Bank of New Zealand says it intervened in foreign exchange markets in an attempt to drive the kiwi lower. It gave no details of the size of the intervention.

The Reserve Bank would impose limits on riskier mortgage lending with smaller deposits if it judged those loans to be a "significant risk" to financial stability.

Increasing pressure in a housing market where supply is failing to meet demand is posing a growing risk to our financial stability, says the Reserve Bank.

Strong overseas demand for the New Zealand dollar is likely to form a major barrier to attempts by the Reserve Bank to bring it down, say analysts.