Vanuatu and the Cook Islands want the United Nations (UN) to make it easier for vulnerable low-lying states to access climate financing.
Officials from both countries say Pacific states graduating from low-income to developed status aren't getting enough help with their climate vulnerability.
Vanuatu's Foreign Minister Ralph Regenvanu said Vanuatu had been lobbying the UN for 15 years to include climate vulnerabilities in its economic assessments.
The climate threats facing Pacific states should be considered before they graduated from least-developed status, which cuts some financial assistance, Mr Regenvanu said.
"We are pushing for Tuvalu and Kiribati and Solomons, for that criteria to be included when considering their graduation because they are seriously vulnerable."
Meanwhile, the Cook Islands, which graduated from least-developed to developed status in July, is looking to seabed mining partly because of recent losses in development assistance, said its High Commissioner to New Zealand.
"This is why for us, economic diversification is currently one of our top priorities," said Elizabeth Wright-Koteka.
Ms Wright-Koteka said climate finance should be dedicated rather than tied to overseas development assistance.