New Zealand will ask international travelers from most countries to show negative COVID-19 test results before boarding flights to the country as new contagious variants of COVID-19 spread across globally.

"Given the high rates of infection in many countries and evidence of the global spread of more transmissible variants, it's clear that most global air routes will be of critical concern for the foreseeable future," COVID-19 Response Minister Chris Hipkins said in a statement.

Hipkins said the pre-departure test requirement would soon expand to all countries and territories excluding Australia, Antarctica and some Pacific Island nations.

Travelers would still have to complete the 14-day mandatory quarantine and undergo testing upon arrival in New Zealand.

Border closure and a strict national lockdown during the initial phase of the pandemic has helped New Zealand keep numbers relatively low, with just over 1,800 confirmed cases and 25 deaths since the pandemic began.

The country last reported a local case nearly two months ago.