The New Zealand Defence Force (NZDF) is helping the United States to train the Japanese military to monitor satellites.
The training comes after the NZDF received US funding to set up a non-classified satellite monitoring hub in Auckland last year.
The defence force sent one trainer to Japan in June, alongside US and Australian instructors, at America's request
"It strengthens New Zealand defence relationships with our partners in the region, as well as demonstrating New Zealand's commitment to collaboration in the space domain," NZDF told RNZ.
Japan is now the third member of a 'Joint Commercial Operations' (JCO) hub, with Australia and New Zealand, who leads the project.
New Zealand has expressed a keenness for more defence ties with Japan.
Helping train the JCO was "a first step" in "building our defence space cooperation", said a briefing to Prime Minister Christopher Luxon for his Japan trip in June.
Japan recently set up a Space Operations Squadron with 20 staff, with the main mission of monitoring "suspicious satellites" and the situation in space.
Another briefing to Luxon said rocket launches were also an option.
"We want to promote New Zealand as a launch site for Japanese companies and the government," it said.
"As well as Rocket Lab, there is also enormous potential for launches from Tāwhaki in the South Island."
Around this time, other official briefings were telling the government that the Tāwhaki joint venture had failed to get any customers, and its efforts to build launchpads at Kaitorete Spit should be scaled back.
Just a fortnight ago, a local aerospace firm signed up with a US surveillance company to launch from the spit.
There are eight JCO hubs worldwide - set up the US Department of Defence - that track both civilian and military movements, problems or threats from satellites or space debris, and provide reports on that to hundreds of organisations.
They are operated under the US Space Force and share an objective of advancing the US's national security objectives.
"The JCO is an extension of the [US] National Space Defense Center operations floor, and it leverages commercial providers to provide diverse, timely Space Domain Awareness in direct support of the NSDC's core protect and defend mission," said an official document.
Both this country and Japan have made several moves this year to more closely align with US defence strategy in the Indo-Pacific.
The NZDF has also done training in space domain awareness for the Ukrainian army, by sending a contingent to Poland.
Other interactions include New Zealand's NZDF Space Operations Centre taking the lead at a recent US-led multinational exercise, "for a mission that involved monitoring replacement of a communications satellite with an adversary satellite in the vicinity".
