"The United States is in close contact with the governments of Jamaica, Haiti, Dominican Republic and The Bahamas as they confront the devastating impacts of Hurricane Melissa," Secretary of State Marco Rubio wrote on X.

"We have rescue and response teams heading to affected areas along with critical lifesaving supplies," he said.

Rubio, a Cuban-American and vociferous opponent of the communist government in Havana, did not mention any contact with Cuba.

A State Department official said to expect "dozens" of US personnel on the ground to assist in rescue operations and damage assessment.

The personnel include teams from Los Angeles and the Washington suburb of Fairfax, Virginia, as well as specialists from a regional hub in Costa Rica.

The pledge of cooperation comes after President Donald Trump's administration cancelled the vast majority of US international assistance by shutting down the US Agency for International Development.

Rubio and Trump have questioned the value of long-term US assistance but promised to keep targeted and immediate aid in crises.

Another official said the ongoing US government shutdown "complicates" the relief effort but that emergency workers were given quick authorization to go ahead.