"Essentially the financial markets are saying that, on a relative basis, New Zealand is a better bet than the United States at the moment. That reflects their very sluggish growth, their very high levels of unemployment and of course the massive debt that they have," he said.
"So on the backdrop of that, if the Reserve Bank was to intervene, you'd have to say up until this point anyway at least, that would have been very unsuccessful, and [there] may not be a lot of reasons to believe it would be successful in the future."
"So while we appreciate all the things exporters are going through, the pressures that the high exchange rate puts on them, I think it's a matter of making sure that we don't just waste taxpayers money by going out there and punting on the exchange rate and getting it wrong," Key said.
"The reality is if you look around the world at countries that have invoked heavy intervention programmes, they've been spectacularly unsuccessful," he said.