"Today, the first phase of a coup to end the era of popular leaders has begun," Maduro said during a televised speech.
Just hours earlier, Rousseff was suspended from office, after Brazilian legislators voted to put her on trial for budgetary discrepancies. Rousseff has denied any wrongdoing, and described her removal as a "farce" and "coup".
"The most brutal of things that can happen to a human being is to be condemned for a crime you didn't commit," she told reporters in Brazil.
Pointing the finger at "Powerful oligarchic, media and imperialist forces," Maduro claimed Rousseff's suspension was "Made in the USA".
"The coup in Brazil is a grave and dangerous sign for the future stability and peace of all the continent. I know they're coming for Venezuela now," he said.
Venezuelan opposition leaders have vowed to remove Maduro from office by the end of the year, possibly through a recall referendum.
Maduro's government has already lost one close ally in recent months, after Argentina elected right-wing businessman Mauricio Macri in presidential elections late last year. In Brazil, Rousseff's Workers Party has long held close ties with Maduro and his predecessor Hugo Chavez.
Rousseff has now been replaced by an interim president, her former political ally-turned rival Michel Temer. On Friday, Temer called for national unity, after appointing an all male, all white, pro-business cabinet. Since Rousseff's removal, Temer has already dissolved the country's human rights ministry, along with ministries for women and racial equality.
Cristina Fernandez de Kirchner was indicted yesterday according to the Daily Mail. The lights are truly going out for South-America.
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