President Nicolas Maduro's comments came a day after he announced the arrests of five opponents he accused of plotting against him to clear the way for a US invasion.
It was one of the more dramatic in a regular series of anti-US harangues by the socialist leader, 54, who is resisting opposition calls for elections to remove him.
"If Venezuela were dragged into chaos and violence... We would fight," Maduro bellowed in a speech to supporters yesterday.
He said that an armed intervention in his country would spark a crisis that would dwarf those caused by conflicts in the Middle East.
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Addressing Trump, he said: "You are responsible for restraining the madness of the Venezuelan right-wing."
Clashes at daily street protests against Maduro over the past three months have left 76 people dead, prosecutors say.
The opposition blames Maduro for an economic crisis that has caused shortages of food and medicine in the oil-rich country.
They regularly accuse him of repressing and jailing opponents. Judicial NGO Foro Penal says there are 383 political prisoners in Venezuela.