Donald Trump has pleaded with Venezuela’s military to support opposition leader Juan Guaido, who has declared himself the country's interim president.
Trump also issued the military a dire warning if they continue to stand with president Nicolas Maduro’s government.
“You will find no safe harbour, no easy exit and no way out. You will lose everything,” Mr Trump said in a speech at Florida International University in Miami before large American and Venezuelan flags.
The US president added: “We seek a peaceful transition of power, but all options are open.”
The Venezuelan military could play a decisive role in the stalemate but has largely remained loyal to Mr Maduro.
In remarks broadcast on state television, Mr Maduro accused Mr Trump of speaking in an “almost Nazi style” and lashed out at his counterpart for thinking he can deliver orders to Venezuela’s military.
“Who is the commander of the armed forces, Donald Trump from Miami?” Mr Maduro said. “They think they’re the owners of the country.”
Mr Trump said “a new day is coming in Latin America,” as he sought to rally support among the largest Venezuelan community in the US for Mr Guaido.
The US recognises him as the country’s rightful president and condemns Mr Maduro’s government and its socialist policies.
As the months-long political crisis stretched on, the military has blocked the US from moving tons of humanitarian aid airlifted in recent days to the Colombian border with Venezuela.
The aid shipments have been meant in part to dramatise the hyperinflation and shortages of food and medicine that are gripping Venezuela.
Mr Trump said of Mr Maduro: “He would rather see his people starve than give them aid.”
Critics say Mr Maduro’s re-election last year was fraudulent, making his second term illegal.
Venezuela’s power struggle is headed to a potentially violent showdown on Saturday, when Mr Guaido will try to run caravans of US humanitarian aid across the Venezuelan border from Colombia.
Mr Maduro denies a humanitarian crisis exists, blaming the Trump administration for mounting a coup against him.
More than 2 million Venezuelans have fled the country in the last two years, most flooding across the border into Colombia, Brazil and Peru.
Those left behind struggle to afford scarce supplies of food and medicine as inflation soars.
Mr Maduro maintains support from Russia, China and Turkey, while Mr Guaido has won recognition from dozens of world leaders in Latin America and Europe, who are demanding that Mr Maduro holds new elections or steps down.
So far, Mr Maduro is not budging. In a recent interview with The Associated Press, Mr Maduro said Venezuela is ready to make an economic rebound once Mr Trump removes his “infected hand” from the country that sits atop the world’s largest petroleum reserves.
Mr Trump urged the Venezuelan military to accept Mr Guaido’s offer of amnesty and refrain from violence against those opposing Mr Maduro’s government.
And he praised the Venezuelan opposition, saying of the people of Venezuela: “They are turning the page on dictatorship and there will be no going back.”
White House press secretary Sarah Sanders said earlier Monday that the US “knows where military officials and their families have money hidden throughout the world”.
Mr Trump said that “socialism has so completely ravaged” Venezuela “that even the world’s largest reserves of oil are not enough to keep the lights on”.
He added: “This will never happen to us.”
“Socialism promises prosperity, but it delivers poverty,” he said.
Mr Trump was introduced by first lady Melania Trump and joined by Commerce Secretary Wilbur Ross, Florida Governor Ron DeSantis and Florida Senators Marco Rubio and Rick Scott, who have all been outspoken in their criticism of Mr Maduro’s government.