WELLINGTON, July 7 (Reuters) - New Zealand Prime Minister Jacinda Ardern said on Thursday regional architecture such as the Pacific Islands Forum was critical in resolving regional problems and local security issues should be resolved locally.

Leaders of the Pacific Islands Forum countries gather in Fiji next week for an annual meeting at a time of growing concern in some countries about China's influence, highlighted this year by a security pact with the Solomon Islands.

"New Zealand is committed to the Pacific Islands Forum as the vehicle for addressing regional challenges," Ardern said in a speech to the Lowy Institute think tank in Australia.

"We have a strong commitment to supporting broader ambitions for our regions security," she said. "Importantly we see local security challenges being resolved locally, with Pacific Islands Forum Members' security being addressed first and foremost by the Forum family."

China's growing sway in the Pacific and the potential for militarisation in the region's small island nations has fanned concern, particularly in Australia and New Zealand as well as their partner, the United States.

China, following on from its pact with the Solomon Islands, has been pushing for a regional co-operation deal with almost a dozen Pacific nations on policing, security and data communications.

As Ardern was speaking in Australia, her government announced a review of defence policy, strategy and planned investment, in part because of an "intensification of geo-strategic competition".

Ardern said that though Pacific co-operation should be shaped by various agreements in place and regional groupings, that did not mean that others would not have an interest in engaging with the region.

"It would be wrong to characterise this engagement, including that of China, as new. It would also be wrong to position the Pacific in such a way that they have to ‘pick sides'," she said.

New Zealand Minister of Defence Peeni Henare, in announcing the defence review, said the military worked daily with allies to protect security and stability in the region.

"The importance of this review is paramount so that we can make sure future investments are fit for purpose in a post COVID-19 environment, a Pacific region grappling with climate change and the intensification of strategic competition, and a world which is seeing a brutal invasion of Ukraine by Russia," Henare said.

Foreign ministers of the Pacific Islands Forum are due to meet in Fiji on Friday but the ministers from both Australia and New Zealand will not be able to attend.

Australian Foreign Minister Penny Wong will be at a G20 meeting in Indonesia while New Zealand's Nanaia Mahuta has COVID-19, their offices said, adding that other top officials would attend instead.