Interior Secretary Sally Jewell leads a U.S. delegation that includes representatives from the Departments of Energy, State and Health and Human Services.
The forum began its meeting Friday in Majuro, Marshall Islands.
"Secretary Jewell's participation in the dialogue and meetings with Pacific leaders will address a range of issues with Pacific Island nations, including global climate change and natural resource management, sustainable development, economic growth and security," the Interior Department said Thursday.
European representatives said they were carrying a message of climate cooperation with them to the meetings.
Scientists say rising sea levels, which may be due to declining polar ice levels, are threatening low-lying regions like Micronesia and the Marshall Islands.
Marshall Islands President Christopher Loeak issued a plea for attention to the issue during an address last year before the U.N. General Assembly.
The U.S. Interior Department has oversight of federal programs and funds Micronesia, the Marshall Islands and Palau.