WELLINGTON (REUTERS) - New Zealand Prime Minister Jacinda Ardern said on Wednesday (June 29) China has become "more assertive and more willing to challenge international rules and norms", and urged the use of diplomacy and economic links to build ties in the Indo-Pacific region.

In a speech at the Nato summit in Madrid, Ms Ardern also condemned Russia's invasion of Ukraine, highlighted the importance of international rules and warned against a new arms race.

"We must stand firm on the rules-based order, call for diplomatic engagement and speak out against human rights abuses at all times when and where we see them," Ms Ardern said.

New Zealand is not a member of Nato, but it is a partner of the Western defence alliance and on occasion New Zealand troops have supported Nato-led operation. In recent months it has contributed to the Nato Trust Fund for operations in Ukraine.

Ms Ardern said the resilience of the Indo-Pacific region must be strengthened through relationships and economic architecture rather than militarisation.

New Zealand has toughened its tone recently on both security and Beijing's growing presence in the South Pacific, in part due to the signing of a security pact between China and Solomon Islands.

It has also taken a strong stance on the invasion of Ukraine, implemented sanctions and sent defence support to Europe.