Doug Emhoff, the husband of US vice president Kamala Harris, also announced on his visit to Apia that the US National Oceanic and Atmospheric Administration will provide extra expertise to the Pacific to assess risks and prepare plans.
This includes committing $US117,000 to strengthen Samoa's National Tsunami Ready Program.
This includes tsunami hazard risk assessment and inundation mapping, community preparedness and response, evacuation mapping and response planning, and tsunami warning.
Emhoff said a core part of US engagement with the region is on the climate crisis, and the USAID money will help local farmers improve their resilience against disasters and help improve messaging around preparedness.
"We know that Samoa and other island nations are on the front lines," he said.
"We know this is an existential threat."
He also spoke at a meeting with Women in Business Development representatives as part of his five-hour visit.
"I've seen Kamala all around the world from South-east Asia to the continent of Africa, meeting with women entrepreneurs and investing in them, because she knows, when you lift up women, you lift up the status of families and communities, and all of society benefits," he said.
He also said US president Joe Biden and Harris are committed to deepening Washington's engagement throughout the Pacific region.
Emhoff visited the Acting Prime Minister, Tuala Tevaga Iosefo Ponifasio, at the FMFMII Building where they exchanged gifts.