New Zealand is weighing the purchase of advanced warships from Japan or the UK to modernise its ageing fleet and bolster its defence capability.

The South Pacific nation, member of the Five Eyes intelligence-sharing network alongside Australia, the US, the UK and Canada, is focused on Japanese Mogami-class or the UK’s Type 31 frigates.

Discussions are under way with the Royal Australian Navy and the UK’s Royal Navy about the frigate replacement and ongoing service arrangements, Defence Minister Chris Penk said in Wellington on Thursday.

New Zealand’s two current frigates, the HMNZS Te Kaha and HMNZS Te Mana, were commissioned in 1997 and 1999 respectively.

“As a remote island nation, maritime security underpins New Zealand’s economic prosperity,” Penk said in a statement. “Yet most ships in the current fleet are expected to reach the end of their design life by the mid-2030s, including the Anzac-class frigates. Without replacement, this would have a significant impact on New Zealand’s ability to protect its maritime interests in the Pacific and beyond.”

The announcement comes as the government plans to lift defence spending to about 2 per cent of gross domestic product from around 1 per cent, citing rising geopolitical tensions. These include incidents such as Chinese warships conducting live-fire drills in the Tasman Sea last year.

Replacement of the frigates is listed as an indicative investment for 2029 to 2039.

Last month, Australia completed a multibillion-dollar contract for the first three of 11 Mogami-class frigates it has agreed to buy. The other eight are meant to be built in Australia, although the details are yet to be announced.

Additional reporting by Reuters