New Zealand naval ships transit contested Taiwan Strait

New Zealand's Defence Force says two of its naval ships have transited the Taiwan Strait, amid tension over the waterway claimed by China and regarded by Taiwan and the United States as international waters.

Prime Minister Christopher Luxon said it was a "routine transit" to join up with a Philippines joint exercise.

Like most countries, New Zealand has no formal diplomatic ties with Taiwan, but Taipei sees it as an important like-minded democratic partner and both maintain de facto embassies in each other's capitals.

The 18 September transits, by naval frigate Te Mana and oiler Aotearoa , were part of a three-month deployment in the Indo-Pacific, a Defence Force spokesperson said.

"New Zealand Defence Force deployments to the region demonstrate our continued interest and commitment to the region," the spokesperson added in a statement.

China's defence ministry did not immediately respond to a request for comment.