At a regional summit of Caribbean countries gathered in Havana, Maduro urged his counterparts "not to give in to the immense pressure from Washington" against his country.
"Venezuela is not going to give in, we will fight," he declared on the margins of the summit.
Maduro also denounced the Organization of American States (OAS) as complicit in seeking to isolate him.
Venezuela's opposition-controlled legislature has asked the OAS to assess whether the Maduro government has violated standards.
Maduro, in turn, has called for a demonstration against the OAS over what he labels as meddling in Venezuela's political crisis.
Under the OAS Charter, the Permanent Council can suspend Venezuela's membership with a two-thirds vote, on the grounds of preserving democracy.
Meanwhile, the oil-rich South American nation is in dire economic straits and the opposition is pushing to remove Maduro through a referendum.
The crisis has been aggravated by electricity shortages that have forced rolling blackouts, school closures and a dramatically shortened work week for public sector employees.
Home to the world's largest oil reserves, Venezuela has skidded into an economic catastrophe as global crude prices have collapsed.
The country, which depends on oil for 96 per cent of its trade revenues is running out of cash to import the food, medicine and other basic goods it buys abroad.
Hyperinflation is forecast to hit 700 per cent this year, threatening Maduro and the socialist economic model he inherited from his late predecessor Hugo Chavez.