Prime Minister Jacinda Ardern says the Government will unveil an economic package designed to get New Zealand "through the worst" of the coronavirus pandemic on Tuesday.

Ardern told TVNZ's Q+A it would be "the most significant package that I will announce while I am Prime Minister".

The Opposition has been demanding the Government take bigger steps to protect Kiwi businesses, with the economy widely expected to go into recession thanks to the spread of the SARS-Cov-2 virus, which causes COVID-19.

The number of confirmed cases is rising exponentially, with more than 155,000 now, and 5802 deaths.

New Zealand now requires all visitors, with few exceptions, to go into self-isolation on arrival.

"This will be the most significant package that I will announce while I am Prime Minister, and I need to make sure we are actually targeting those businesses that need that help the most, and it's sufficient to make a  difference to keep people in work," Ardern told Q+A on Sunday morning, defending the time it's taken to ready the economic package.

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"We gave ourselves a week - that is even then an extraordinarily limited time for what we needed to do."

Ardern will present the package to Cabinet on Monday, and formally reveal its contents on Tuesday.

She said it would target both employers and employees, with a focus on those likely to be hit hardest, rather than wider general support. Wage subsidies will be a part of it, she confirmed. 

"You've seen other countries that have done just singular payments - for me... I don't know that that would be sufficient to keep people connected to the labour market... It will be significant, it will be designed to carry people through the worst of this event."

She wouldn't reveal the total cost, but said it would be the biggest "one-off" package she'll ever announce.

As for whether a recession or even depression is possible, Ardern said she had advice two weeks ago on the likely effects of COVID-19 that is already out-of-date, but is predicting a "significant" hit to GDP.

New Zealand has had six confirmed cases of COVID-19, all in people who picked it up overseas.