The 4th US National Climate Assessment, released at the weekend, is the federally sanctioned work of about 300 academics and experts on the threat posed by climate change.
The assessment devotes a chapter to the US Pacific.
Zena Grecni, is the Project Specialist for the Pacific Islands Regional Climate Assessment based at Honolulu's East-West Center.
She said in the four years since the last report, threats from climate change had increased substantially.
"Especially with sea level rise. It's accelerated and is now actually beginning to damage beaches, eco-systems, infrastructure like roadways and airports and housing," Ms Grecni said.
"The projections have been continually revised to be more severe and more quick."
Freshwater systems would also be compromised, coral reefs destroyed, and the region's biodiversity would come under greater stress, she said.