BNZ currency strategist Mike Burrowes said the kiwi's fall was not directly related to the raising of the US debt ceiling.
He said there were other factors at play, such as a bout of risk aversion sweeping through the market on nervousness in the Italian banking sector.
Shares in UniCredit, Italy's largest bank, were temporarily suspended yesterday due to extreme market volatility. There were also concerns about global economic growth, which were acting against the riskier currencies.
The passing of the debt deal meant that part of the US dollar's reputation as a safe haven currency had been restored, for the time being at least.
Some foreign exchange participants are calling the kiwi higher, but BNZ expects it to hold at around present levels for the next 12 months.
"We don't believe that this is structurally normal and that the currency is going to keep appreciating over the long term, but for now the reasons for it to stay high are reasonably well supported," he said.
Westpac's Speizer said some computer valuation models suggested the kiwi was heavily overvalued.
"With the debt crisis out of the way, relationships will be restored, which will mean the overvaluation of the kiwi will have to correct itself," he said.
Markets are turning to June quarter unemployment data, due tomorrow, for indications as to whether the currency's strength could be justified by domestic fundamentals.