Venezuela's top diplomat called a senior U.S. official "petulant" and ill-mannered on Wednesday in response to her contention that sanctions were intended to change the government, not topple it.
Foreign Minister Delcy Rodriguez was responding to State Department Assistant Secretary of State Roberta Jacobson's comments explaining a U.S. declaration that Venezuela is a security threat and its sanctioning of seven officials earlier this week.
"In a rude and petulant manner, Mrs. Jacobson tells us what to do," Rodriguez told local TV. "I know her very well because I have seen her personally, her way of walking, chewing. You need manners to deal with people and with countries."
The moves by President Barack Obama's administration have infuriated President Nicolas Maduro's socialist government, which has accused Washington of planning military attacks and wider Cuba-style trade sanctions. State TV has been playing old footage of the U.S. invasions of Grenada and Panama.
Maduro has also asked parliament to grant him six-month special decree powers, given the "imperialist" threat, a move foes have condemned as a power-grab and attempt to distract Venezuelans from shortages and recession.
The U.S. government, which endorsed a short-lived 2002 coup against Maduro's predecessor Hugo Chavez, has repeatedly denied it is conspiring.
"The goal of these sanctions is to persuade the government of Venezuela to change its ways, not to remove that government," the State Department's Jacobson tweeted.
The U.S. move is enabling Maduro to play the nationalist card skillfully employed by his charismatic mentor Chavez, whose populist style and focus on social welfare made him hugely popular among the poor for most of his 1999-2013 rule.
Washington's measures have also wrongfooted Venezuela's opposition which, while agreeing with U.S. accusations of rights abuses and corruption, do not want to be associated with outside interference.
With Venezuelans increasingly fed up with soaring prices and shortages from milk to car parts, the opposition had hoped for a protest vote in its favor at upcoming parliamentary elections.
But political analysts believe the U.S. spat may give Maduro a bounce, albeit a temporary one.
Venezuela's allies are supportive, with Cuba mocking the U.S. moves despite its own recent rapprochement with Washington.
"We will respond to this grotesque, illegal, shameless, unheard of and unjustified meddling by the United States," added Ecuadorean President Rafael Correa, announcing a meeting on the issue next week of foreign ministers of regional bloc UNASUR, which has generally backed Venezuela's stance.