Weekly-tested border workers are being given the option of saliva swabbing to reduce the "discomfort" of regular nasal swabs.
COVID-19 Response Minister Chris Hipkins said on Wednesday more than 1400 border workers can look forward to the change, which he said came after "extensive due diligence".
"We are now satisfied that a combination of the two tests, along with frontline managed isolation workers being very close to being fully vaccinated, will continue to provide the assurances we need at the border while reducing the level of discomfort among frontline staff," Hipkins said.
"What today's announcement means is that workers who have to be tested for COVID-19 once a week because of their important roles can now have saliva swabbing incorporated as part of that mandatory regime.
"As part of a phased rollout beginning in June, these workers can choose to be part of a regime of multiple saliva tests, and a single nasopharyngeal swab each fortnight.
"We're satisfied we're starting the introduction of saliva testing at the right time but will move with caution to ensure compliance with the Border Workforce Testing Register."
Hipkins said border workers have expressed discomfort at receiving a nasal swab once a week, and with the border workforce now being vaccinated, they feel more protected and less likely to get infected. But they are also less likely to be symptomatic if they do.
"The addition of more frequent saliva testing is designed to address this," Hipkins said.
"Expert advice is that will work well in detecting any cases in border workers when it's carried out at an increased frequency and appropriately complemented by nasopharyngeal swabs."
Asia Pacific Healthcare Group (APHG) won the tender for the contract, after approval from the Ministry of Health. It has been heavily involved in New Zealand's response to COVID-19, processing a third of all tests carried out in New Zealand to date.
The Government started offering saliva testing in January at quarantine facilities as a "precautionary measure" in the wake of more contagious variants of the coronavirus popping up in managed isolation facilities.
The Government soon came under fire from the Opposition over how long it was taking for saliva testing to be rolled out more widely in isolation facilities.
Prime Minister Jacinda Ardern appeared frustrated during questioning from Opposition parties National and ACT in February at what she described as them "trying to have an argument" about its effectiveness.
"There's no defence of this on this side of the House about the use of saliva testing. Who would disagree with using something that isn't nearly as invasive or creates nearly as much barrier as what a nasal PCR test does?" Ardern said at the time.
"We view saliva testing favourably; anything that is easier for the workforce is something we'd like to see. However, we of course also rely on the advice of our officials, so we're very pleased that they are meeting with some of those who have been advocating for the use of saliva-based testing...
"We've already got it underway in rollouts in some of our facilities and I look forward to greater use of it across the board."