China has tested a submarine-launched ballistic missile in the South Pacific, and New Zealand's Foreign Minister Winston Peters has said it's unwelcome and threatens regional peace.

New Zealand was told about the test just hours before it happened on 6 July. The missile carried a dummy warhead and landed in waters China said were set aside for the exercise. China's government described it as a routine annual military training activity.

Peters disagreed. He said the missile landed in the South Pacific Nuclear Free Zone — a region where nuclear weapons are banned under an international treaty. Peters said China's test breaks that agreement and goes against a shared Pacific vision New Zealand and its neighbours have been building together.

This isn't the first time

China tested another long-range missile in the South Pacific in September 2024. That was the first such test in that region in 44 years. Both New Zealand and Australia expressed concern about it at the time.

The timing of this latest test is worth noting. Australia and Fiji signed a joint defence agreement on 30 June — just days before the missile test. News reports suggested China's test was a deliberate response to that new alliance.

There's also a wider background. In 2025, China sent three naval ships into the Tasman Sea — the water between New Zealand and Australia — without warning. New Zealand's Defence Minister at the time called that a "wake-up call." This time, at least, New Zealand got a few hours' notice.

What comes next

Peters said he would talk to other Pacific countries about what happened and that New Zealand would keep watching the situation with its regional allies.

Prime Minister Christopher Luxon confirmed he had spoken to the leaders of Australia and Fiji about their new defence alliance. Luxon said New Zealand is interested in possibly joining that agreement, though the government hasn't made a final decision yet.

New Zealand is in a tricky position. It does significant business with China, it has security commitments to countries like the US and Australia, and it tries to be a trusted voice in the Pacific. When China acts unilaterally in the region like this, those interests can pull in different directions.

Peters's message — that Pacific countries should not accept these missile tests as normal — is essentially calling for the region to work together on a common standard. Whether other countries respond with a coordinated approach or just individual statements remains to be seen.