The United States has imposed sanctions on the son of Venezuelan President Nicolas Maduro for serving in his father's "illegitimate regime". The action freezes any assets Nicolas Ernesto Maduro Guerra has in the United States and bars American individuals or institutions from doing business with the 29-year-old. "Maduro relies on his son Nicolasito and others close to his authoritarian regime to maintain a stranglehold on the economy and suppress the people of Venezuela," US Treasury Secretary Steven Mnuchin said in announcing the action on Friday. "Treasury will continue to target complicit relatives of illegitimate regime insiders profiting off of Maduro's corruption." The latest US action comes as Mr Maduro moves to consolidate his hold on power after what Caracas called a failed coup attempt by opposition leader Juan Guaido. Mr Guaido, the leader of the opposition-controlled National Assembly, is recognised by the United States and more than 50 other countries as Venezuela's acting president. In targeting Mr Maduro's son, the Treasury noted that he was a member of the pro-government Constituent Assembly, which Mr Maduro has used to sideline the National Assembly. The US statement slammed the Constituent Assembly as having been "created through an undemocratic process instigated by Maduro's government to subvert the will of the Venezuelan people". It also said Mr Maduro Guerra "has profited from Venezuelan mines along with Maduro and his wife, Cilia Flores", and engaged in propaganda and censorship efforts on behalf of his father's government. Venezuela called the sanctions an attack on the president himself. "They announce illegal measures against Constituent Assembly member Nicolas Ernesto Maduro Guerra, with the obscure goal of personalising a continuous attack on the Bolivarian revolution and the leadership of the president of Venezuela," the foreign ministry said. The US had previously sanctioned the Venezuelan president and eight members of the Constituent Assembly, as part of a wide-ranging effort that has also targeted the government's oil revenues and access to international financial markets. The new sanctions came in a week of simmering tensions. On Thursday, the US government announced indictments of two Venezuelans on money laundering charges, including Mr Maduro's former electric power minister and another top ministry official. The country's electrical grid was hit with major, days-long outages in March, another sign of crumbling infrastructure and services that have contributed to a mass migration of Venezuelans. On Wednesday, the Venezuelan government said it foiled a plot to assassinate Mr Maduro, who accused the United States, Colombia and Chile of complicity. At least six of the alleged plotters were arrested, Communications Minister Jorge Rodriguez said. Mr Maduro has claimed to have been a target of assassination plots before, including an apparent attempt to blow up a drone near him at a military parade in August 2018. His former intelligence chief, Christopher Figuera, arrived in Washington this week after fleeing Venezuela in May following Mr Guaido's failed attempt to spark a military uprising on April 30. Mr Figuera told the <em>Washington Post</em> he had plotted with Defense Minister Vladimir Padrino and Supreme Court chief Maikel Moreno to oust Mr Maduro during the uprising, but they got cold feet. Both Mr Padrino and Mr Moreno remain in office. Ivan Simonovis, a former Venezuelan national police chief who fled house arrest in Caracas where he was being held on murder charges, surfaced in Washington this week to talk to US politicians about "criminal activities" of the Maduro government. He backed up many of Mr Figuera's allegations. Mr Simonovis said an interview in Miami that Maduro senior has the choice of leaving or being overthrown. Asked if there is, in fact, a drive afoot to remove him, Mr Simonovis demurred. "At this point, there are very high-level political decisions. I am simply part of the 'how' in that decision, not the 'whether'."