No Wellington cases as NZ bans NSW travel

New Zealand officials have lengthened a travel ban from NSW and won't rule out further border closures as the wait for test results in Wellington goes on.

New Zealand hasn't had community transmission of COVID-19 since February, an 118-day run that is currently under threat.

Wellington played host to a traveller from Sydney last weekend, who tested positive for the virus on his return home.

The man and his partner wined and dined across the capital, visiting restaurants and the national museum, Te Papa.

The visit - known as the "Sydneysider Scare" - has prompted thousands to isolate and get tested, and the government to enforce new restrictions on movement and gatherings.

So far, in 6000 Wellington tests since the visit, none have returned positive.

"Obviously I'm encouraged by what we're seeing but it's still quite early," COVID-19 Chris Hipkins said.

The NZ government will hold a virtual cabinet meeting on Sunday, after two more days of test results, to decide on any possible lockdown or new restrictions.

"We will be looking for the (wastewater) test results from Wednesday and Thursday this week, we should have those back by Sunday," Director-General of Health Ashley Bloomfield said.

"We're not out of the woods and we need people to be tested."

Quarantine-free travel has been suspended from NSW until at least July 7.

As the Sydney cluster seeps into Melbourne, with two new cases returning to the city from a party, Mr Hipkins said NZ would be constantly vigilant to Australian cases and extend trans-Tasman border closures when needed.