The Prime Minister's adamant we're not overreacting to the coronavirus outbreak.

From today, foreigners who have been in, or transited through, mainland China will be refused entry into New Zealand.

New Zealand citizens or permanent residents are exempt, but must self-isolate for 14 days after arriving in the country.

It comes as the worldwide cases for the virus crosses 14,000. 

Prime Minister Jacinda Ardern told Mike Hosking it's not a decision she made lightly.

"Ultimately, this is about a precautionary approach. I acted on the advice of health officials. It's certainly not a matter of doing something just because someone else has."

A plane load of New Zealand, Australia and Pacific Island nationals is expected to leave Wuhan, the epicentre of the coronavirus, today, bound for Auckland. 

New Zealanders on the evacuation flight will then be transferred to a military training camp at Whangaparaoa, where they'll spend two weeks in quarantine.

People are being charged $500 for the flight, which Ardern says is a reasonable sum.

"It's far less than what most people would pay otherwise and most of course would need to get home at some point.

"I don't think its unreasonable and I certainly haven't had any complaints raised with me."

Over the weekend, Australia announced passengers will no longer be charged to board its flight.