Maduro meanwhile announced his government was blocking social media platform X for 10 days, after accusing the site's owner Elon Musk of an "attack" on his reelection.
Election authorities declared Maduro the winner of the July 28 vote but have yet to release detailed results, leading left-wing allies Brazil, Colombia and Mexico on Thursday to reiterate a joint call on the National Electoral Council (CNE) to disclose polling records.
The Venezuelan opposition, which claims to have won in a landslide, has cried foul. The official results declaring Maduro the winner sparked protests last week that left at least 24 people dead, according to rights groups.
"If Maduro chooses to stay by force, the only thing we will see is a wave of migration like never before: three, four, five million Venezuelans in a very short span of time," opposition leader Maria Corina Machado -- who was barred from running in the election -- said in a video conference with Mexican news outlets.
According to the United Nations, more than seven million Venezuelans have fled the country of 30 million since Maduro came to power in 2013, mostly to other Latin American countries and the United States.
Maduro has overseen an unprecedented economic crisis, including an 80 percent drop in the once-wealthy oil-rich country's GDP, amid domestic economic mismanagement and international sanctions.
Washington has spearheaded sanctions against the Maduro regime and on Thursday threatened that further measures would be taken if Maduro were to arrest opposition leaders Machado or Edmundo Gonzalez Urrutia, a retired diplomat who stood as a candidate after agreeing at the last minute to replace his barred colleague.
"I think that would be a step that could mobilize the international community even more, even those that might be somewhat sympathetic and don't want to rattle things too much in Venezuela," Francisco Mora, the US ambassador to the Organization of American States, said at the Atlantic Council, a Washington-based think tank.
Machado -- who says she fears for her life -- and Gonzalez Urrutia have been in hiding for more than a week.
'International hysteria'
The public prosecutor's office has opened a criminal probe against the two opposition leaders for "usurpation of functions, diffusion of false information, incitement to disobedience of the laws, incitement to insurrection" and "criminal association."
Citing his fear that he would be "jeopardizing" his freedom if he did so, Gonzalez Urrutia on Wednesday defied a Supreme Court summons over the disputed results.
The court summoned all presidential candidates, including Maduro, and other opposition politicians, some of whom did attend. Maduro is due to appear before the court on Friday.
Fellow left-wing governments from Brazil, Colombia and Mexico praised the verification process undertaken by the court but released a statement saying that they "start from the premise that the CNE is the organ legally mandated to transparently disclose the electoral results."
Critics say the court, and the electoral authority, are unfailingly loyal to Maduro, who wants the body to simply "validate" his victory.
The CNE ratified Maduro's victory with 52 percent of votes, but did not publish detailed results and even claimed to have been hacked.
The opposition has launched a website with copies of 84 percent of ballots cast, showing an easy win for Gonzalez Urrutia with two-thirds of votes. The government claims those are forged.
The opposition and several observers accuse the CNE of inventing the hack at the government's behest to avoid publishing the real results.
Vice President Delcy Rodriguez on Thursday hit out at the international community and critics on social media for "an international hysteria around the (election) minutes, they could even make a Netflix series."
Maduro on Thursday night told a rally of supporters that X, formerly Twitter, would be "withdrawn from circulation" by the state agency in charge of telecommunications. He did not give details on how the suspension would work.
"No one will silence me, I will confront the espionage of the technological empire," he said, accusing American billionaire Musk of "inciting hatred and fascism."
Jennie Lincoln, head of the Carter Center delegation that was invited to monitor the Venezuelan election, told AFP that that US-based organization had "no evidence" of a cyberattack.
In addition to the protester deaths, Maduro announced the death of two police officers and the arrest of more than 2,200 people.
