The environmental organisation Greenpeace says the voice of vulnerable Pacific countries will be heard at climate change talks in Mexico, but its power is limited.
The United Nations climate change conference has begun in Cancun.
It follows an international summit in Kiribati earlier this month which resolved to take a declaration to Mexico urging that the immediate effects of climate change be addressed, and calling for fast funding to combat it.
Greenpeace International's climate policy director Wendel Trio says that declaration will be heard in Cancun but Pacific countries do not have the economic power to push decisions through.
"That message is heard but unfortunately many of the biggest emitting countries are not yet ready to take the kind of strong action that is needed to fulfill the wishes of the Pacific Islanders, and clearly that is a pity."
Wendel Trio says cooperation between Pacific countries and other vulnerable countries has increased their impact on negotiations.