Australia's new government is under pressure from other Pacific leaders to sign a pledge of support for the Paris climate accord, and declare climate change the "single greatest threat to the livelihoods, security and well-being" of the region.
The Sydney Morning Herald reports a joint security declaration from the 18 members of the Pacific Islands Forum, obtained by Fairfax Media, will be considered next week at the summit in Nauru.
It comes as prime minister Scott Morrison faces political pressure from conservative MPs to water down or abandon emissions reduction commitments Australia made under the Paris agreement.
As his newly formed government attempts to move past the chaos of last week's leadership crisis, Mr Morrison will not attend the Nauru meeting, sending new foreign minister Marise Payne in his place.
The draft "Biketawa Plus" regional agreement covers a range of issues including crime, humanitarian assistance, and the environment, and has enjoyed the support of the Australian government during recent negotiations.
The paper says the Pacific nations have pushed for recognition of the threat of climate change, given the particular vulnerability of low-lying island communities in the region.
The document Australia will be asked to sign includes the statement: "We reaffirm that climate change remains the single greatest threat to the livelihoods, security and well-being of the peoples of the Pacific and our commitment to progress the implementation of the Paris agreement."
Jonathan Pryke, director of the Lowy Institute's Pacific Islands programme, said Pacific nations were crying out for Australia to show strong commitment to climate change action and there were concerns about Morrison's record on the environment.
"This is the man who brought a lump of coal into Parliament," Mr Pryke said, referring to Morrison's stunt during question time last year. "That imagery has made it out into the world."
Mr Pryke added: "There's a lot of disagreement in the Pacific but they are unified on one thing above anything else and that's climate change."
Australian Conservation Foundation chief executive Kelly O'Shanassy said the government needed a plan to reduce emissions so it can do its "fair share" as a wealthy and powerful country.