New Zealand on Monday reopened its borders to international visitors from visa-waiver countries such as Japan, South Korea and the United States, continuing the country's staggered reopening after more than two years of border restrictions.

Tourists from visa-waiver countries and territories can now enter if they are fully vaccinated against COVID-19 and return a negative pre-departure test.

The New Zealand flag flies in front of The Beehive in Wellington in May 2020. (Getty/Kyodo)

Tourism Minister Stuart Nash said in a statement the reopening marked a "milestone for visitors" from key markets such as Japan, the United States, Britain, Germany, South Korea, Malaysia and Canada.

The move follows the earlier reopening of the border in April to vaccinated Australian citizens and permanent residents.

Travelers will be required to undertake two self-tests using rapid antigen test kits upon arrival and again five days later and report both results to the Health Ministry.

The final stage of border reopening is slated for October and will see the resumption of normal visa processing for all visa categories.

New Zealand maintained some of the world's most strict border controls for much of the pandemic in a largely successful bid to keep the virus at bay.

The population of about 5 million has seen about 933,000 cases of COVID-19, and just 707 deaths so far, well below many comparable nations.

Related coverage:

China suspends freight train operations with North Korea amid virus

South Korea to allow taking masks off outside from May 2

New coronavirus strain found in northeast Japan city