Venezuelans are expected to gather for mass protests on Wednesday after opposition leader Juan Guaidó called for fresh demonstrations.
It comes the day after President Nicolás Maduro said he had stopped an “attempted coup” by the opposition.
“Today we continue,” Mr Guaidó tweeted. “We will keep going with more strength than ever, Venezuela.”
Mr Guaidó says the armed forces now back the protesters, but Mr Maduro says they have not turned against him.
In a fiery television address on Tuesday, Mr Maduro accused protesters of “serious crimes” which he said would “not go unpunished”, and said the US was plotting against him.
Mr Guaidó declared himself Venezuela’s interim leader in January and has been recognised by more than 50 countries, including the US, the UK and most in Latin America.
But Mr Maduro – backed by Russia, China and the top of the country’s military – has refused to cede leadership to his rival.
US Secretary of State Mike Pompeo said military action was “possible” if necessary but that the US would prefer a peaceful transition of power.