Guaido declared himself Venezuela's rightful leader a week ago and says the nation "is set on change".
The sanctions aim to cripple Maduro after the United States and other countries recognized Juan Guaido, the head of the National Assembly legislature who has declared himself Venezuela´s acting president.
What may be most striking about all this is that such hard-knuckle power plays aren't really in Bolton's job description. "If the aim of the United States is to invade, they'll have a Vietnam worse than can be imagined".
"Any violence and intimidation against USA diplomatic personnel, Venezuela's democratic leader, Juan Guaido, or the National Assembly itself would represent a grave assault on the rule of law and will be met with a significant response".
Workers wait for customers at their vegetable stand at a wholesale food market in Caracas, Venezuela, on January 28, 2019.
Maduro also expressed "pleasure and gratitude" for Russian President Vladimir Putin's help.
Notes Mr Bolton held at a Monday briefing containing the words "5,000 troops to Colombia" have also raised questions. The Pentagon refused to discuss the matter, referring all questions to the White House.
But Maduro said Trump would have "blood all over his hands" if violence breaks out in the country.
However, given the failure of previous rounds of dialogue, including one led by the Vatican, opponents are suspicious, believing Mr Maduro uses them to quell protests and buy himself time.
The sale of oil is the single most important income stream to the Venezuelan government. So, what's the true intent and goal of the United States and Guaido? When asked about a possible military option in Venezuela, Guaido said all options were on the table, CNN said. "Now, I've been in touch with numerous refineries - there is a significant amount of oil that's at sea, that's already been paid for - that oil will continue to come to the United States".
On Tuesday, Guaido urged Venezuelans to step outside their homes and workplaces for two hours on Wednesday in the first mass mobilisation since last week's big protests.
U.S. President Donald Trump spoke to Venezuela's self-proclaimed interim president by phone on Wednesday, reiterating support for his "fight to regain democracy", as Washington's push to force socialist President Nicolas Maduro from power picked up steam.
Venezuelan opposition's new envoy in Washington Carlos Vecchio, second from right, accompanied by Sen. "One is internal pressure, people out in the streets. The third is worldwide pressure".
"This money is worth nothing", said Josefina, who declined to give her last name for fear of repercussions from the government. Almost two-thirds go to sleep hungry at night. Hundreds have also been arrested, including children.
Maduro said the talks could be held with mediation of other countries.
A former union leader, bus driver and foreign minister, Mr Maduro has overseen a shrinking economy and the migration of three million Venezuelans fleeing shortages and hyperinflation. The Donald Trump administration said that there would be a "significant response" if personnel of America were intimidated or threatened.