Wellington will return to alert level 1 from 11.59pm tonight, eight days after a Covid-infected Sydney tourist flew out of the capital.

However "we still need to remain vigilant," Covid-19 Response Minister Chris Hipkins has warned.

"There is never room for complacency."

The virus can incubate for up to 14 days, but director-general of health Ashley Bloomfield told reporters that the likelihood of people in Wellington still incubating the virus was "now very low".

Wellington has been in alert level 2 since 6pm on Wednesday last week, following a weekend visit from a Sydney tourist who later tested positive for the Delta variant.

There are no new Covid cases in the community today and four to report in managed isolation facilities.

Hipkins said there were currently 30,000 Covid vaccine doses in stock, but there was another delivery expected today. Stocks will drop to their lowest point next Tuesday.

He said supplies will get very tight, but the Government had made a decision to get supplies out the door and into people's arms rather than staying in freezers.

Wellington 'dodged a bullet'

With no positive results from community and wastewater testing, Otago University epidemiologist Professor Nick Wilson said the situation in the capital was looking "pretty favourable".

"So we've probably dodged a bullet on this one. But it's still important that people do get tested, and that there remains a heightened level of surveillance for Wellington."

Wilson felt the capital's scare had proven a "missed opportunity" for requiring masks and mandatory QR-code scanning around the city.

"These sorts of measures would have made this particular episode less of a worry if those extra safeguards had been in place – but it's good news that the Government is looking into these."

Trans-Tasman bubble re-opens to some states from Monday

Also, Hipkins has announced that from 11.59pm on Sunday, July 4, the pause on the transtasman bubble will lift for the states of South Australia, ACT, Tasmania and Victoria.

Travellers from Australia will require a pre-departure test within 72 hours of their flight, which will need to be negative.

He said a high level of risk remained for NSW, as well as for Queensland, Western Australia and the Northern Territory. The pause on those states will be reviewed on Tuesday, July 6.

New South Wales reported 19 new community cases earlier today.

No new cases in community today

Bloomfield said tracking and testing the 2609 contacts of the Sydney tourist was "way more than we have ever done before".

Over 950 people still needed to remain in isolation for the full 14 day period, he said.

There had been more than 8200 tests in Wellington in the last week.

"Let's keep the scanning numbers up."

Hipkins said wastewater results showed no detection at any sites in the greater Wellington region.

Of the 7250 tests were processed yesterday nationwide, all tested negative.

The number of active cases in this country is now 30, the Ministry of Health said.

Two of the four new MIQ cases today are from Kuwait, and two are from the Netherlands.

The ministry said 93 per cent of the 2609 Wellington contacts of the infected Sydney tourist had now returned a negative test.

Nine additional people have had a swab and are awaiting a result, 11 people have been granted a clinical exemption and eight have returned overseas, which means their home jurisdiction will be following up with them.

"The remaining contacts are being followed up by contact tracing teams," the ministry said.

Meanwhile both of the two contacts in New Zealand connected to the positive case who worked in the Newmont Granite goldmine north-west of Alice Springs, Northern Territory, have tested negative.

"Health officials were also advised of 40 people in New Zealand who have been classified as contacts of the air steward in New South Wales, who had tested positive.

"All of these people have been contacted, had their first test and all results are negative. A number of these people are continuing to isolate and will undertake day five testing, based on their contact classification."

There were 2003 tests in the Wellington region yesterday, the ministry said.

Level 2 was extended at the weekend until 11.59pm tonight.

The only person the tourist has infected so far is his partner, who had one dose of vaccine.

"That has of course not changed our behaviour but reinforced the reasons why we've been cautious," Ardern said this morning.

"Regardless of what happens with alert levels at any given time, we want everyone to be on alert. Get a test if you've got symptoms."

Yesterday Ardern signalled a move to introduce mandatory QR scanning in bars and restaurants, wider mask use at alert levels, and a legal requirement for all workers to be fully vaccinated to work at the border.

The Government also paused the transtasman bubble with Australia on Saturday until 11.59pm tonight.

Ardern said yesterday that the action was taken because there was too much uncertainty about how far the Delta variant had spread across Australia, even though there were two states that still appeared to be Covid-free

Pre-departure testing is likely to be imposed on travellers from Australia, and this morning Ardern said people will need appropriate forewarning of such a requirement.

"What we're mindful of is, first of all, people need to know which states we may re-open to.

"No point someone from a closed state getting a pre-departure test."

New South Wales' Greater Sydney area, the Northern Territory's Greater Darwin region and Western Australia's Perth and Peel regions are now all in lockdown.

Restrictions are also in place across South Australia - which has no cases - and Queensland, with the latter "on the verge" of a lockdown, according to the state's premier.

The NSW cluster reached 130 cases yesterday, while there were seven cases linked to the Northern Territory outbreak and three to the Perth and Peel cluster.

Queensland recorded two new cases yesterday, and Premier Annastacia Palaszczuk warned of an impending lockdown due to a Covid-positive miner, linked to the NT outbreak, who had been infectious in the community with the highly-infectious Delta strain.

Australia has now mandated Covid vaccinations for aged care workers, as well as all quarantine workers and their household contacts.