International condemnation
The United States, the European Union, the Vatican and major Latin American nations including Mexico, Argentina and Chile have all condemned the new body, saying it undermines democracy and stokes tensions in Venezuela.
Mercosur, a South American trading bloc, was meeting on Saturday in Brazil to decide whether Venezuelan should be suspended from it for "breaching democratic order."
The legitimacy of the Constituent Assembly has been thrown into question by claims of fraud, most notably by a British-based firm, Smartmartic, which was involved in supplying the technology for the July 30 vote.
Smartmatic said the official turnout figure had been "tampered with" and exaggerated by at least one million voters.
The opposition has vowed to maintain street protests against the assembly, despite being increasingly sidelined and despondent.
Maduro's security forces have stepped up pressure on dissenters. The Vatican has urged them to show restraint after a death toll from four months of unrest of 125.
A prominent opposition leader, Leopoldo Lopez, was thrown back in military prison after the intelligence service roughly ended a brief spell of house arrest granted last month.
Another leader, Caracas mayor Antonio Ledezma, was released back into home detention on Friday after being hauled away the same day as Lopez.
