Maduro's oil-rich leftist government has been hurt hard since US President Donald Trump on Monday ordered a freeze on all Venezuelan government assets in the United States and barred transactions with its authorities.
In response, Maduro "has decided to not send the Venezuelan delegation" to the latest round of talks, which were scheduled for Thursday and Friday and were to be held in Barbados and mediated by Norway, according to a statement.
Maduro attributed the cancellation to "the grave and brutal aggression" being "continuously... carried out by the Trump administration against Venezuela, which includes the illegal blocking of our economic, commercial and financial activities," the statement read.
The dialogue was to be held with representatives of opposition leader Juan Guaido, the speaker of the National Assembly who proclaimed himself acting president in January.
Guaido is calling for new elections under the talks, while Maduro, who retains support from Venezuela's military, demands a "democratic cohabitation" and refuses to leave office.
Guaido is now recognized as Venezuela's leader by more than 50 countries.
Opposition negotiator Stalin Gonzalez tweeted from Barbados that his side "would continue to search for an end to the crisis and rescue our democracy through truly free elections."
Venezuela said it is not permanently cancelling the talks, but rather will "review the mechanism of the process" to make sure it is "in harmony with the needs of our people," the statement said.
Trump's measures were just the latest in a string of sanctions imposed on the Maduro regime in a bid to force the socialist leader from power.
In Caracas, thousands of government supporters dressed in red and waving Venezuelan flags marched against the US sanctions on Wednesday.
Made up mostly of civilian militia and public sector employees, the crowd chanted: "Yankee go home!" and "Hands off Venezuela!"
"We're struggling against this war that's making life impossible," Elena Flores, a 62-year-old government worker, told AFP.
Trump "is nervous, he's anxious, he's power-hungry, he wants to get his hands on Venezuela," she added.
Washington has threatened to "use every appropriate tool" to oust Maduro, and warned Venezuelan allies Russia and China on Tuesday against doing business with the regime.
China responded to the sanctions by telling the US to stop "bullying" other countries.
Speaking at a small meeting in the east of Caracas, Guaido insisted the US sanctions would affect only top regime officials and not the general population.
"They're against the regime, against Maduro, the product of arrogance," he said, also calling for the release of opposition legislator Juan Requesens, who was arrested a year ago and is accused of being behind an alleged drone attack against Maduro.
Maduro's inner circle, however, refutes such claims.
"Enough impunity!" tweeted Defense Minister Vladimir Padrino. "Those who began the 'game' of asking for sanctions ... with political purposes should be punished by law."
Venezuela's opposition considers Maduro a usurper over his re-election last year in a poll widely viewed as rigged.