NZ naval vessel sailing through Taiwan Strait 'routine movement' - Defence Minister

The defence minister has confirmed a New Zealand military ship has sailed through the Taiwan Strait, describing it as a "routine activity".

The Strait is part of the South China Sea, an ocean which several countries have contested territorial claims.

In a statement, Judith Collins said the HMNZS Aotearoa sailed through the Taiwan Strait with Australian vessel HMAS Sydney from 2pm local time on Wednesday.

"This was a routine activity, consistent with international law, including the right of freedom of navigation as guaranteed under the United Nations Convention on the Law of the Sea," Collins said.

"This was a routine movement from one point in the Indo-Pacific to another and not directed at, or requested by, any particular country," she said.

A NZDF vessel last passed through the Taiwan Strait en route to Qingdao in 2017.

Respect for international law was important to New Zealand and it was exercising its rights under the convention, Collins said.

However, she said the country was concerned about rising Strait tensions.

"We have called for the peaceful resolution of cross-Strait issues through dialogue.

"New Zealand has consistently adhered to our one China policy for more than 50 years. Nothing has changed," Collins said.

A spokesperson for the Chinese Ministry of Foreign Affairs said "China handles foreign warships' transit through the Taiwan Strait in accordance with laws and regulations".

"Meanwhile, we stay vigilant against any acts that might jeopardize China's sovereignty and security," they said.

A Japanese ship has also sailed through the Taiwanese Strait this week, but the ABC is reporting this is a separate activity to the joint Australia and New Zealand voyage.