WASHINGTON—The U.S. government is considering restricting trades in Venezuelan debt as it seeks to punish President Nicolás Maduro for undermining the country’s democracy, according to people familiar with the matter.

The unusual move would temporarily ban U.S.-regulated financial institutions from buying and selling dollar-denominated bonds issued by the Republic of Venezuela and state oil company Petróleos de Venezuela SA, according to a person who was briefed on the proposal.

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