The penalties focus on current or former Venezuelan government officials accused by the US of supporting President Nicolas Maduro's creation of a constituent assembly.
That body has been given the job of rewriting Venezuela's constitution, in what the United States has said was an attempt by Maduro to solidify his hold on power.
The assembly, formed by a July 30 election, has declared itself superior to all other government institutions and has ousted Venezuela's outspoken chief prosecutor.
Many of those targeted by the US are regional representatives on the new assembly, including Adan Chavez, the brother of Venezuela's former leader, who died in 2013.
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Adan Chavez has been appointed secretary of the new assembly and also is a former governor and minister in Venezuela's government.
The sanctions freeze any assets the individuals may have in the US and prevent Americans from doing business with the Venezuelans.
The US has said the vote to create the assembly was illegitimate and a sign that Maduro is trying to strengthen what the US calls his "dictatorship."