Prime Minister John Key is urging New Zealanders not to panic about an uncertain world economy.

The news that Greece has rejected a bailout offer that came with harsh austerity measures has driven our dollar to a five year low.

There are also worries about the impact of plummeting dairy prices.

John Key said he is not worried about our economy heading into a downturn.

"I really urge people to take a deep breath. Yes dairy prices are down a little bit, but there are a lot of other factors in our economy."