Bolton also warned Russia not to interfere in the region, as he bashed Cuba, accusing Havana of being the power behind Maduro. He said the United States was providing humanitarian support and "other things I am not going to talk about."
"If this effort fails they will sink into a dictatorship from which there are very few possible alternatives," Bolton said of opposition leader Juan Guaido's "courageous" effort to oust Maduro. He insisted this was "not a coup," and indicated he was not surprised by events.
In particular, he called on Vladimir Padrino, the minister of defense, to join the opposition. Bolton indicated he was among key figures who were expected to join the opposition had not yet done so. "We want as our principle objective the peaceful transfer of power," Bolton said.
Guaido earlier published a video alongside a small contingent of uniformed military personnel and armored vehicles in which he called for an uprising to end the "usurpation" of Maduro.
He stressed this was the beginning of the final phase of the effort to oust Maduro, known as Operacion Libertad, or Operation Liberty.
"The National Armed Forces have made the correct decision, they have the support of the Venezuelan people," Guaido said.
Guaido also called on the Venezuelan people to take to the streets to support the "democratic forces" and "recover the country's freedom" after sympathetic military officials released Leopoldo Lopez, the opposition leader who has been held in custody since 2014 for leading anti-government protests.
Venezuela has been rocked by mass demonstrations since Jan. 10, when Maduro was sworn in for a second term following a vote boycotted by the opposition.
Tensions escalated when Guaido, who heads Venezuela's National Assembly, declared himself acting president on Jan. 23, a move which was supported by the U.S. and many European and Latin American countries.
It is unclear how widespread the military defections seen on Tuesday have become amid economic and humanitarian crises in the Latin American nation.