Pacific island leaders on Friday demanded urgent action from the global community to address climate change, following fresh warnings that the region would be hit harder than anywhere else on Earth.

In a communique issued at the end of a week-long gathering in the Samoan capital Apia, the Pacific nations highlighted the "significant vulnerability" they faced and called for international aid to deal with the challenge.

"Leaders called for urgent, ambitious action from the global community to address climate change, including the provision of finance," the 18-member Pacific Islands Forum (PIF) said.

The forum includes countries such as low-lying Kiribati and Tuvalu, which are at risk of being swamped by rising sea levels.

Fiji, which has been battered in recent years by devastating cyclones that have become more extreme as global warming affects weather patterns, has offered permanent refuge to the peoples of Tuvalu and Kiribati.

But the nations agreed relocation is not the answer, and the bigger issues of global warming and sea-levels needed to be addressed in the exposed island states which are located in remote areas of the Pacific Ocean.

A World Bank report presented during the forum said climate change would hit the Pacific harder than anywhere else on Earth, and the region's tiny island nations need major international aid to deal with the challenge.

In the communique, PIF recognised "the significant vulnerability of forum island countries to the adverse impacts of climate change".

"With regard to the issue of fragility and vulnerability, leaders reiterated their call to the World Bank for an expanded definition of 'fragility' to take into account the vulnerabilities faced by Forum Island Countries," it said.

Aside from climate change, the forum also condemned nuclear tests by North Korea and its threats to fire missiles towards the US territory of Guam.

Although Guam is not a member of PIF, an attack on it "constitutes a threat to the wider Pacific islands region", members said.

The communique said forum members, who oversee some of the world's most lucrative fishing waters, were committed to deregistering any North Korean trading or fishing vessels currently flagged on Pacific states’ shipping registers.