The National Assembly, overseen by opposition leader Juan Guaido, has declared Dec. 6 parliamentary elections in which allies of Maduro's ruling socialists won a majority as "illegitimate", and over the weekend voted to prolong its mandate.
Venezuela's mainstream opposition parties boycotted the vote on the basis that they would not be free and fair. Maduro, who calls Guaido a US-backed puppet seeking to oust him in a coup, has said the electoral conditions were as transparent as when the opposition won a majority in the parliament in 2015.
"In the face of unconstitutional claims to self-proclaim term extensions that are not warranted, we trust that the justice system will do its job with an iron fist," Maduro said in a state television appearance with members of the military, Reuters reported.
The parliament's move to extend its term comes as dozens of legislators facing criminal investigation for alleged crimes like treason have fled the country. Others have expressed unwillingness to continue serving in congress due to what they describe as persecution the government.