An official said there had been a "small upswing" in private jets arriving in Queenstown.
In Auckland, long-time real estate agent to the wealthy, Graham Wall, was helping two billionaires.
"I've had calls from people wanting to come here. One lot of Americans we've just taken around [properties] in the Bay of Islands.
"They think New Zealand looks the best place to ride out the virus."
US president Donald Trump yesterday declared a national emergency as cases continued to rise and public life ground to a halt as schools closed, top sport was suspended and Broadway shut its doors.
New Zealand has so far escaped the community transmission which triggered skyrocketing numbers of sick in other countries, such as Italy and Iran.
The American family in New Zealand, which included elderly members, wanted to buy a New Zealand property but after discovering that - under foreign ownership laws - wasn't possible they switched to hunting for a luxury rental.
They could stay in New Zealand for three months as visitors, but one had told Wall a border closure trapping the family here would be welcome.
"The wife, who's in her 80s, she said, 'Graham, if they shut the f***ing world and we're stuck in New Zealand that would be our dream come true."
An elderly Australian billionaire was also looking for a Kiwi coronavirus safe haven, Wall said.
Before Ardern's announcement that people travelling to New Zealand would have to self-isolate for 14 days, Wall's Australian client was due in on Wednesday by private jet before travelling on to Queenstown.
"You're pretty safe on any plane, but you're at high risk in the airport. On a private jet you can clear customs on the jet and get straight into your car."
Before the announcement, Wall had been expecting more calls.
"Given the situation in America, there will be more."
Queenstown Corporate Jet Services chief executive Peter Van Dy said there had been a "small upswing" in private jet arrivals in recent weeks, where the airport's corporate jet terminal facility handles about 250 landings a year.
He attributed the resilience of private jet activity at its facilities at Queenstown, Christchurch and Wellington airports to New Zealand's reputation as a safe haven.
For high-net-worth individuals and families, it made sense to use a private jet rather than commercial services during a global health scare, Van Dyk said.
From March 7 until yesterday nine private aircraft landed in New Zealand, two - from Hawaii and Perth - at Queenstown Airport, according to the New Zealand Customs Service.
Other arrivals in the last week were four from Samoa, Sydney, the Gold Coast and Hong Kong at Auckland Airport, where a spokesman said there hadn't been a noticeable increase in private jets arriving in the past month, compared to previous years.
Kerikeri, Christchurch and Wellington airports also received private jets from Lord Howe Island, Perth and Sydney respectively.
The resident who spotted the five private jets at Queenstown Airport said one included a Bombardier 6000 worth "well over $50 million".
"Five jets in one day is a busy day out there... It's normal at Christmas and [during] the Winter Festival. But it's pretty quiet now."