The remarks came four days after the Trump administration recognized Venezuelan National Assembly leader Juan Guaidó as interim president after Guaidó and his supporters asserted that the election previous year that kept Maduro in power was illegitimate.
"Do not test the United States on our resolve to protect our people", Pompeo told the U.N. Security Council Saturday.
France and Britain joined Spain and Germany in turning up the pressure on Maduro, saying they would follow the USA and others in recognizing Guaido as president unless Venezuela calls a new presidential election within eight days.
"Today, Israel joins the United States, Canada and most of Latin American and European states".
Meanwhile, on Saturday, Maduro seemed to go back on his decision to expell U.S. diplomatic staff from Venezuela.
Vecchio is a former aide to Leopoldo Lopez, another opposition leader who is under house arrest in Venezuela.
Washington said it was ignoring the order as it no longer considered Maduro the president - but withdrew non-essential staff and argued that Maduro still bore responsibility for diplomats' safety.
The embattled leader said on Wednesday that Caracas would break off diplomatic relations with the United States and gave it a 72-hour deadline to pull out its diplomats from the country.
As the deadline expired, Maduro said he had begun negotiations to set up within 30 days an Interests Section in Caracas to maintain a minimum level of diplomatic contact, similar to the arrangement the United States had with Cuba until their 2015 rapprochement. Invoking constitutional provisions, National Assembly leader Guaido declared himself interim president until there are new elections.
The European Union's foreign policy chief, Federica Mogherini, said that if there is no announcement of a new election in the next days, the 28-nation bloc "will take further actions, including on the issue of recognition of the country's leadership".
Guaido was swarmed by television cameras as he stepped out of a Roman Catholic church on Sunday and said he'll continue to press forward with plans to install a transitional government in Venezuela led by himself and members of the National Assembly.
"Any violence and intimidation against USA diplomatic personnel, Venezuela's democratic leader, Juan Guiado, or the National Assembly itself would represent a grave assault on the rule of law and will be met with a significant response", Bolton tweeted Sunday.
Venezuela's President Nicolas Maduro speaks during a news conference at Miraflores Palace in Caracas, Venezuela January 25, 2019. "It's that simple, especially, when it comes to Venezuela", he added.
The United States, which made a decision to recognize the country's National Assembly leader Guaido as Venezuela's official leader earlier this week, has demanded allies "pick a side" in Venezuela, and to "financially disconnect" from Maduro's regime until the dictator cedes to his countrymens' call to step down.
Private military contractors who do secret missions for Russian Federation flew into Venezuela in the past few days to beef up security for President Nicolas Maduro in the face of US -backed opposition protests, according to two people close to them.
President Maduro fears a foreign military intervention in Venezuela and is ramping up its armored forces along the Colombia border.
At the same time, supporters of opposition leader Juan Guaido handed out leaflets to soldiers, urging them to reject the socialist leader and explaining how they could be eligible for amnesty if they help return Venezuela to democracy.
"If they want to leave Venezuela, they should all go, and now".
He "asked the Lord to seek and find a just and peaceful solution to overcome the crisis that respects human rights and exclusively seeks the good of all people".
Maduro's reelection previous year was contested by the opposition and rejected by the US, EU and United Nations as a sham - but he has until now retained the loyalty of the powerful military. Maduro has since backed down and has agreed to 30 days to finalize the diplomats' roles in Venezuela.