Former Venezuelan prosecutor Franklin Nieves called on the Obama administration to sanction other officials involved in the trial of Leopoldo Lopez. Nieves said the Maduro government brought "sham" charges against the opposition leader, ultimately sentencing to almost 14 years in prison.

Nieves, who has fled to the United States, where he is seeking political asylum, told the Associated Press that he deeply regrets his role in the proceedings and now wants to help U.S. authorities expose how his country's judiciary is controlled by the regime of embattled President Nicolás Maduro.

Nevertheless, Nieves said he and his family plan to return to Venezuela as soon as circumstances allow it.

"I don't want to stay in the United States,'' he insisted. "Once the situation in Venezuela changes, all of us will leave for Venezuela and help the country produce and move forward."

In the meantime, though, the former prosecutor has come under criticism in the United States despite his revelations. Patricia Andrade, who heads the Venezuela Awareness Foundation, a Miami-based exile group, questioned Nieves' about-face this late in the game.

"Asylum is reserved for victims of political persecution," Andrade told the AP. "Nieves is a persecutor with a criminal record stretching more than a decade."

The former official's call for additional sanctions, however, has since been echoed by senior U.S. diplomat Thomas Shannon, who said on Thursday that if approved to his new State Department position, he may seek to put further pressure on Maduro's regime, according to Agence France-Presse.

The Obama administration's relationship with Caracas "will depend of what happens around the legislative elections and what happens around the issue of political prisoners," Shannon, who has been nominated as the next undersecretary of state for political affairs, told the Senate Committee on Foreign Relations.

Maduro, for his part, on Tuesday threatened to sue the United States over an earlier executive order labeling Venezuela a threat to U.S. national security, United Press International reported.