New Zealand will be one of the lowest ranked countries in terms of power by 2030 according to an index ranking 25 countries in Asia, The Lowy Institute Asia Power Index says.
New Zealand was currently placed 12 of 25 nations - but future trends saw it slip back to 22 by 2030 in terms of economic, military and demographic resources.
Australia was also forecast to slip from its current ranking of 6 to 13.
The index takes into account economic resources, military capability, resilience, future trends, diplomatic influence, economic relationships, defence networks and cultural influence.
The methodology of the indicators can be found here.
The index reached as far west as Pakistan, as far north as Russia, and as far into the Pacific as Australia, New Zealand, and the United States.
New Zealand's strongest performance was in resilience and defence networks measures, ranking sixth in both measures with scores of 64.4 and 39.3 points.
"Ranked 2nd for government effectiveness and political stability among Index countries, behind only Singapore.
"Second-most carbon efficient economy among Index countries, with 0.05 kg of CO2 emissions per US dollar of GDP."
Australia was currently placed as the sixth most powerful nation in the region, scoring 32.5.
However it was expected to fall to 13th place of 25 by 2030 according to the growth of neighbouring countries.
In 2030 the United States will only be ahead of China in military spending while India will have the largest working-age population.
Australia's strongest performance was in the defence networks measure, ranking in 2nd place with a score of 69.7.
It also performed well in the resilience measure, ranking in 3rd place and scoring 77.8 points.
Australia's lowest ranking occurs in the future trends measure, in 13 place with a score of 3.2.