Prime Minister Jacinda Ardern and Japan's PM will negotiate an information-sharing agreement as New Zealand looks to strengthen its ties with the country amid rising tensions with China.
In a joint statement, Ardern and Japan Prime Minister Fumio Kishida said the arrangement was about protecting peace and security in the Indo-Pacific region.
It comes amid concern over a China-Solomon Islands security cooperation agreement signed earlier this week, raising fears of "serious risks to a free and open Indo-Pacific".
"We are well aligned in our views and approaches to the challenges facing our region," Ardern said.
"The global strategic environment is volatile and we face unprecedented challenges."
Foreign affairs expert Robert Patman told AM the information-sharing agreement would help hold other countries accountable for international wrongdoings.
"It's very important for us as a country because, although we're a small player, we are globally active in terms of trade," said Prof Patman, from the University of Otago. "This sharing of information is designed to make sure that countries which engage in unilateral actions - such as China in relation to the South China Sea or Russia in relation to Ukraine - that these sort of authoritarian forces are held in check."
Prof Batman said China wouldn't be "ecstatic" about the agreement between Japan and New Zealand.
"It may well make some grumbling noises, in diplomatic terms, in the direction of New Zealand," he told AM host Ryan Bridge.
The Government in conjunction with the Ministry of Foreign Affairs and Trade had been trying to upgrade New Zealand's relationship with Japan for several years, Prof Patman said.
"It was making good progress before the interruption of COVID-19 and I think developments this year have given [the relationship] added impetus.
"The China security agreement with the Solomon Islands and also, of course, the Russian invasion of Ukraine - these are both seen as… challenges to the international rules-based order which both Japan and New Zealand hold very closely."
Ardern on Thursday warned against "pigeonholing" China as being aligned with Russia over its invasion of Ukraine.
But she also expressed concern about "militarisation" in the Pacific, saying there was "no need" for the China-Solomons security deal.