Coronavirus: Jacinda Ardern to step-up border enforcement, threatens fines, forcible quarantines

Jacinda Ardern says border enforcement will "step up" to prevent further COVID-19 cases spreading throughout New Zealand.

Following the meeting of her COVID Cabinet Committee on Wednesday, the Prime Minister said further decisions had been made, with the expectation a higher proportion of returning Kiwis could have had contact with the coronavirus.

"Every New Zealander coming through our borders will be screened," she announced.

"If they are symptomatic, they will be tested and they will be put in isolation in an approved facility. If they are not symptomatic, but they have no plan or ability to self-isolate, they will also be placed in an approved facility.

"If they live in a city outside of the one in which they have landed and have no ability to transport themselves home whilst maintaining isolation, they will also be placed in an approved facility."

Recent arrivals who have an appropriate plan to self-isolate will be checked on by police in the coming days.

"If they are not following requirements they will be fined and they will be quarantined," Arden said.

"These measures area tough but reflect the higher risk these New Zealanders pose."

She added she was sure they would be keen to keep other Kiwis safe.

New Zealand going into lockdown

From Wednesday night, New Zealand will be in lockdown for at least four weeks in an attempt to minimise the spread of the virus, which has infected more than 200 people locally.

The lockdown means people must remain indoors, non-essential businesses will close, schools are shut, and travel is severely limited.

"If everyone reduces down their contacts, stays at home, that's one less person that's at risk of picking it up who's less likely to pass it on to three other people and then three other people and then three other people - which is roughly the transmission rate," Ardern told The AM Show on Tuesday.

"So everyone needs to play their part, and please do. It's not just about your life, it's about others."