Palau's President says he and other Pacific leaders will make an "impassioned plea" that Australia take climate action at the Pacific Islands Forum.
Tommy Remengesau said a key topic at the meeting in Tuvalu will be developing countries not doing enough to tackle the climate crisis.
It comes after several Pacific leaders made a veiled jab at Australia's climate policies on Wednesday and called for a global end to coal production.
In a joint declaration, members of the Pacific Islands Development Forum called on governments of countries with high carbon emissions to stop hindering climate change efforts.
It also asked them to "refrain from using carry-over credits as an abatement for the additional Paris Agreement emissions reduction targets," a system controversially used by Australia.
Mr Remengesau said Palau would be one of the countries calling on Canberra to do more at this month's forum.
"I share the concern of the rest of the Pacific that Australia as a big brother can do more than what they're doing right now. And should take the lead. And this is not something that we're hesitant to say. We're already asking Australia to take a more active partnership role."
Mr Remengesau said it was hard to expect European countries to do more if Australia was not taking the lead.