Fiji's interim prime minister Frank Bainimarama has accused the global community of abandoning Pacific island nations to "sink below the waves" instead of tackling climate change.

Opening a regional summit, he singled out "selfish" Australia for criticism, saying there is "collective disappointment and dismay" in the Pacific at the failure to address climate change.

"The rising sea levels caused by global warming threaten the very existence of some of our neighbours - Kiribati, Tuvalu and the Marshall Islands," he told the Pacific Islands Development Forum (PIDF).

"[They] are already swamping the coastal areas of many Pacific nations, including Fiji.

"Yet if anything, the collective will of the global community to adequately address this crisis is receding."

Sorry, this video has expired Watch Rear Admiral Frank Bainimarama's full speech.

Indonesian president Susilo Bambang Yudhoyono was guest of honour at the summit.

He pledged $US20 million to help Pacific island states combat climate change, in a bid to boost the "green economy" in the region.

Rear Admiral Bainimarama said there had been "a distinct change of rhetoric" from Australia on climate change since conservative Prime Minister Tony Abbott was elected last year.

Earlier this month, Mr Abbott said he would not adopt any climate policies that would "clobber the economy".

"I appeal to Australia and other countries not to behave selfishly over the catastrophic prospect facing small island developing states," Rear Admiral Bainimarama said.

"History will judge you harshly if you abandon us to our apparent fate of sinking below the waves because you don't want to make the necessary adjustment to your domestic policies."

Mr Yudhoyono said climate change was among the greatest challenges facing the world and announced Indonesia was allocating US$20 million to help minimise its impact in the Pacific.

"Indonesia has a strong commitment to broaden its network of cooperation with PIDF countries in mitigating the impact of climate change," he said.

Mr Yudhoyono also said he wanted two-way trade between Indonesia and Pacific island nations to triple to $US1 billion in coming years.

AFP