New Zealand will require all internationally arriving people - including returning Kiwis - to self-isolate for a fortnight as the country locks down to ward off the spread of coronavirus.
Prime Minister Jacinda Ardern announced the measure on Saturday after an emergency meeting of cabinet.
"We do not take these decisions lightly," she said.
"New Zealand will have the widest-ranging and toughest border restrictions of anyone in the world."
Ms Ardern said the measure applied to people, and not goods, though gave an exemption to people arriving from the Pacific - a region largely devoid of the virus.
The decisions will take effect as of midnight NZDT on Sunday.
New Zealand has just six cases of the disease to date, and none that have been transmitted through the community.
Ms Ardern also announced cruise ships would not be allowed to dock in New Zealand until June.
The decision will be reviewed in 16 days.
Earlier on Saturday, the government announced the cancellation of a national remembrance service in honour of the Christchurch mosque attacks, which took place on March 15 last year.
Australia-New Zealand ODI cancelled
Australia's one-day series against New Zealand has been abandoned, with the Black Caps team rushed home in the wake of the new border requirements.
"A consequence of this is that we need to get our team back to New Zealand before the restriction is imposed, meaning it will not be able to participate in the two remaining Chappell-Hadlee fixtures," a New Zealand Cricket spokesman said.
"Arrangements are at this moment being made to fly the bulk of the squad home this evening."
The teams were meant to play three Twenty20s against each other in New Zealand, starting from 24 March, but those matches have also been called off.
"NZC believes both these series can be replayed in their entirety at a later and more appropriate date," the spokesman said.
"NZC understands and supports the government's position. This is a time of unprecedented risk and peril, and the personal health and well-being of our players is paramount."
Australia defeated New Zealand in the first of three ODI games at the SCG on Friday by 71 runs, which was played in an empty stadium because of the global health pandemic.