All of New Zealand's borders will close to non-residents in an attempt to stop the spread of COVID-19.

Only New Zealand citizens or permanent residents and their families will be able to enter the country from 11:59pm on Thursday.

Prime Minister Jacinda Ardern announced the decision on Thursday evening, saying it follows a number of tourists refusing to isolate.

"I've been increasingly concerned visitors to New Zealand are not adequately self-isolating or refusing not to and that is an unacceptable risk that we must end," she told media.

The law also extends to the Pacific Islands.

People from the Pacific were exempt from the previous rule of mandatory self-isolation for 14 days upon entering New Zealand.