Washington DC - President Donald Trump said on Friday that "Cuba is next" in his latest threat against the Caribbean island, as he dismissed concerns that recent American military actions would cost him political support.

Cuba's communist government has faced mounting pressure from Trump, who imposed a de facto oil blockade in January and mused about "taking" the country.

Speaking at the Saudi-backed FII Priority investment forum in Miami, Trump said his Make America Great Again (MAGA) movement wanted "strength" and "victory," citing the January raid where US forces seized Venezuelan leader Nicolas Maduro.

"I built this great military. I said, 'You'll never have to use it,' but sometimes you have to use it," Trump said.

"And Cuba is next, by the way. But pretend I didn't say that."

Trump did not specify what he planned to do with Cuba, telling the media to "disregard that statement" before repeating "Cuba's next" to laughter from the audience.

In his Friday speech, the Republican president also made a teasing comment, dubbing the Strait of Hormuz the "Strait of Trump."

Cuba's leader Miguel Diaz-Canel said last week that any external aggressor would face "unbreakable resistance," even as the country was hit with two nationwide blackouts in a week.

Cuba has been under a US trade embargo since shortly after Fidel Castro's 1959 revolution. Relations thawed in recent years but have plunged again since Trump took office for his second term, with the US president seeking to tighten Washington's grip on Latin America.

A top Cuban diplomat earlier said Havana was willing to continue talking with Washington, but discussing changes to its political system was out of the question.