Under the sanctions, US firms and individuals are banned from doing business with Mr Maduro.
The election on Sunday was marred by violence, with widespread protests and at least 10 people killed.
President Maduro hailed the poll as a "vote for the revolution".
The opposition coalition, which boycotted the election, said 88% of voters had abstained. It has refused to recognise the election, and called for more protests later on Monday.