The sanctions stop short of cutting off U.S. imports of Venezuelan oil that are crucial to Venezuela's economy and USA oil refiners.
The Constituent Assembly, which plans to stay in place for two years, was originally tasked with rewriting the oil-rich, cash-poor country's 1999 constitution, promulgated by the late Hugo Chavez, Maduro's mentor.
"The Maduro dictatorship continues to deprive the Venezuelan people of food and medicine, imprison the democratically-elected opposition, and violently suppress freedom of speech", the statement said.
The U.S. thus far has refrained from imposing broader economic sanctions on Venezuela that would affect the country's oil exports to the U.S.
Maduro, the 54-year-old successor to former socialist dictator Hugo Chavez, has faced widespread protests following an economic collapse caused by a decline in oil prices, runaway inflation and severe shortages of basic goods. White House press secretary Sarah Huckabee Sanders, when asked a few minutes later to elaborate, said, "We leave all options on the table and we're not taking any of those things off". The ban prohibits Americans or USA financial institutions from buying bonds to prop up President Nicolas Maduro's government or the state run oil company.
Mnuchin, however, left the door open for rolling back these sanctions if the Maduro regime restores democratic processes.
"We urge those within the regime, including those who have been sanctioned, to distance themselves from the violence and the dictatorship", Mnuchin told reporters at the White House.
Venezuela will "take all measures at its disposal", said Arreaza.
"Obviously, the US has a lot of influence over the Venezuelan economy", an administration official told reporters.
Earlier on Friday, Washington announced new sanctions that bar dealings in new debt bonds issued by the Venezuelan government and state-owned oil company Petroleos de Venezuela (PDVSA).
Under the order, the Treasury Department intends to cut off financing to the "illegitimate" Maduro government.
Trump has even raised the specter of military action, something Maduro has sought to use to unify the armed forces. "We try to integrate all elements together".
Venezuela's President Nicolas Maduro holds the country's national flag during a rally in Caracas, Venezuela, July 27, 2017. Clearly, though, Trump and Pence have stopped worrying about subtlety and are going to get more and more assertive in South America.