On Tuesday, Ledezma and Lopez were arrested for violating the terms of their house arrest, according to country's Supreme Tribunal of Justice.
"The Federal Government demands immediate release of [Lopez and Ledezma] and all other detainees," Demmer said at a press briefing, adding that the legitimacy of the Constituent Assembly, elected under such circumstances, could not be recognized.
Last week, Venezuela held an election to select members of the Constituent Assembly, a new legislative body with the power to amend the constitution. The election was held amid mass protests across the country that have already resulted in over 110 deaths. Maduro convened the Constituent Assembly to restore peace in a beleaguered country, but the opposition said that a new legislative body would only serve to solidify the current government's hold onto power.